Timeline thoughts, part 1:
Pre FNAF 2:
Fred Bear's Family Diner opens.
A child is killed outside of Fred Bear's Family Diner (FNAF 2 minigame Take Cake to the Children)
HYPOTHESIS: The Freddy played in this mini-game is Golden Freddy. The gold coloration is due to age and wear. Spring-Bonnie is the same color and the Phantom Animatronics (save for the Marionette), which are now quite old themselves, are as well (though these are admittedly hallucinations)
Fred Bear's Family Diner sells out to Fazbear Entertainment (FNAF 2 Night 5 Phone call "We're gonna the original restaurant owner" "It's been closed for years though")
Freddy Fazbear's Pizzeria opens in various locations utilizing 2 multipurpose, Spring-Lock suits, both animatronic and wearable. Golden Freddy and Spring-Lock Bonnie (FNAF 3, Night 2. "Right now we have two specially designed suits, that double as both animatronic and suits.") (FNAF 3 Golden Freddy mini-game)
Accident occurs at primary location involving an employee and a spring-lock suit. Spring-Lock suits are locked away in safe rooms found at every location. These rooms are not on the digital blue-print, are invisible to the animatronics, and have no cameras. (FNAF 3 Night 3. "Every location is built with one extra room that is not included in the digital map layout program for the animatronics or security system. This room is hidden to customers, invisible to animatronics, and is always off camera.) (FNAF 3, Night 4. "After learning of an unfortunate incident at the central location, involving multiple and simultaneous spring-lock failures, the company has deemed the suits temporarily unfit for employees." "... The classic suits are being retired to an appropriate location while being looked at by our technicians.") (FNAF 3, Night 5. "The safe room is reserved for equipment and/or other property not being currently used..." "... The spring-Bonnie animatronic has been noticeably moved.")
Golden Freddy and Spring-Bonnie are replaced with inappropriate/irrelevant costumes with the intention of replacing them with appropriate animatronics later. (FNAF 3, Night 4. “Until replacements arrive, you'll be expected to wear the temporary costumes provided to you. Keep in mind that they were found on very short notice, so questions about appropriateness/relevance should be deflected.”)
HYPOTHESIS: Chica and Foxy were the irrelevant suits found on short notice, Regular Freddy, and Regular Bonnie were the eventual replacements for Golden Freddie and Spring-Bonnie. Chica and Foxy also got full on animatronics.
Golden Freddy and Spring-Bonnie costumes at all locations are sealed away in the safe rooms. (FNAF 3, Night 6. “Due to budget restrictions, the previously mentioned safe rooms are being sealed at most locations. Including this one.” “Nothing is being taken out beforehand...”
FNAF 2 Freddy's Fazbear's Pizza location constructed.
HYPOTHESIS: The previous location discussed in FNAF 2, Night 1 is the FNAF 1 Freddy Fazbear's Pizza. Given that there were only 6 or so years between FNAF 2 and FNAF 1, and that some of that time had to be spent with no open Freddy Fazbear's Pizza locations, it is unlikely for the FNAF 1 building to be newly constructed and in that rundown of a condition in only. Therefore I propose that the central location prior to FNAF 2, which was stated to have been left to rot, was the FNAF 1 building. Which they returned to once the company had to restructure and reduce costs.