The locations [FNAF1-2-3] (P&P5)

The Fnaf2 location is shown in the SAVETHEM minigame, during Fnaf2. The Withered animatronics lie in the Parts/Service room with Withered Freddy roaming around the building following the Puppet. The Toy animatronics are on the stage, Toy Freddy winking, Toy Chica without her beak, Toy Bonnie with his guitar. Mangle is strangely the only animatronic moving by itself in Kid's Cove. Five kids are found dead on the floor. Six red blood spots lie on the ground, one of which beneath the Puppet box, the place where the Puppet leads you to. 

The Fnaf1 location is shown in the End-of-Night's minigames of Fnaf3. It lacks the kitchen, both the closet and Pirate Cove are hidden (with Foxy inside), but everything else is there. The bathrooms seem to be sealed. We can even see the secret safe room where William used to hide and which is hidden from cameras; it appears to be open and you can find three arcade cabinets there. Eight black blood spots lie on the floor (one of which can only be seen through the static but it's there) and two are on the tables in the middle room.

Many floors have a black and white tile floor. They are roughly consistent with what we see in the Fnaf1 camera feed, although the area around the show stage should be red (this may be due to the black and white filter over the building).
Actually... look at the other location, at the Fnaf2 map... You can find in there an area where the tiles are black and red. It does match the position inside of the Fnaf1 location but... Think about the camera feed of Fnaf2, the place has black and white tiles there, not red... weird.

Wait a second... try to compare the two locations... the rooms with tiles are a perfect match! WHY?
Not only that, but the Parts/Service rooms of both locations also match, and the blood spots are in the same exact corresponding position, even the hidden one we pointed out earlier! The only two blood spots that don't match are the ones on the tables (but after all tables could realistically be moved out at some point).

There is only one possible explanation (aside from a weird coincidence/mistake where Scott used different assets by recreating the rooms with tiles and the blood spots, while also putting them in the same exact position, which seems at the very least unlikely):

The Fnaf2 location and the Fnaf1 location share the same building!

Could it really be that the two locations lie in the same building, one being the other one but renovated, with new rooms and moved walls?

What if we try to merge the two maps?   [Fnaf2 into Fnaf1]

Everything fits so smoothly: the tiled rooms, the blood spots, the Parts/Service rooms, Pirate Cove and the closet having a Fnaf2 counterpart.

And we have an answer to a tiny detail about Fnaf2 we asked ourselves many times: where the heck is the safe room? Is it where Parts/Service is? Maybe behind it?

The answer is NO, the safe room in Fnaf2 is likely sealed and is behind the music box!

Was that the place where the Puppet was leading us to during SAVE THEM?

Was he leading us to the safe room, where the yellow suit was used?

TLDR

The Fnaf1 location and the Fnaf2 location share the same building, one being renovated into the other.

The safe room in Fnaf2 is walled behind the music box, and it is the place where the Puppet leads us to during SAVE THEM.

Likelihood meter: 90%

The details here are massive. The sprites of the blood stains were changed from one minigame to the other (you can see how in the picture), same for the tiled rooms. There was intent in Scott placing them. If all of this really accounts to nothing or to a red herring, we should just stop theorising about Fnaf, because we can't trust any detail to be factual and Scott himself told us to look at details (remember toy chica's beak made of 2 pixels).

Impact: High

Implications:

• There are nine blood spots in total, eleven if you count the two on the tables in Fnaf1. Could they represent the victims or their number is meaningless?
• Which location is older? Is the Fnaf1 location of the minigames actually older than the Fnaf2 location? [see P&P5+]
• What if the rooms with a tiled floor all belong to an older location in some way?
• At the end of Fnaf2, Phone Guy states "when the place eventually opens again I’ll probably take the night shift myself". Did he do so in that same location after all?

Connections with other theories: This theory adjoined with the theory of the original showtime happening earlier than Fnaf1 (P&P3) implies that the building went through two renovations. It isn't that unlikely actually, since the Fnaf2 location was a grand reopening of the previous iteration of Freddy's Fazbear Pizza.
Situational details:

• Golden Freddy appears in the same place in both Fnaf1 and Fnaf2, since the Fnaf2 Office and West Hall are aligned.
• The toy animatronic's stage in Fnaf2 has walls different from the others: maybe it was built afterwards?

• In one of the dream sequences of Fnaf2, the puppet is indeed present in the Fnaf1 building.

Problems: The budget for renewing the Fnaf2 location into Fnaf1 location was low according to Phone Guy. Could they afford structural changes still?

Feedback from comments:

Phone Guy had these comments about the "old location":

"I want you to forget anything you may have heard about the old location. ... That old restaurant was kind of left to rot for quite a while."

"I'm sure you've noticed the older models sitting in the back room. Uh, those are from the previous location."

This sort of implies there is another location. However Phone Guy also states:

"We're gonna try to contact the original restaurant owner. Uh, I think the name of the place was... 'Fredbear's Family Diner' or something like that."

So it's possible he was referring to Fredbear's. He followed his statements about the previous location with somthing that sounds like "we at Fazbear Entertainment" do things differently:

"but I want to reassure you, Fazbear Entertainment is committed to family fun and, above all, safety."

That location being Fredbear's is in line with what he says. Furthermore this would explain the presence of the Puppet.

Finally nothing forbids the old location to be in that same place: Phone Guy says "that old location" but he refers to the Fnaf2 location with "that location" as well.