I spotted Fire Alarms in Buildings (2.0) - #1854 by El_Chupacabra]knockoff SpectrAlerts and BG-12s at a cruise port in Mexico a few months ago. Ironically, these devices were installed in the past year to replace real BG-12s and SpectrAlerts.
The most egregious “legitimate” (UL listed product from a major brand) knockoff I know of is the Imgur: The magic of the Internet Autocall MD (Imgur: The magic of the Internet here’s a closeup of the MD’s cards), which is practically identical to the Simplex 2001. According to Destin, the 2001 Kidde/Thorn Datasheets - #9 by Destin]predates the MD. It appears that there was absolutely no attempt to distinguish the MD from the 2001. While I can’t confirm whether these panels were also released after the 2001, other honorable mentions include the http://firealarmresources.com/wp-content/uploads/2013/06/Standard-Electric-Time-SET-7080-1980-Ad.pdf Standard Electric Time SET-7080 (it even has a march time card!) and https://www.ebay.com/itm/National-Time-and-Signal-Series-7000-Fire-Alarm-Control-Panel/114154430828?hash=item1a9422616c:g:ArwAAOSwv-5edCyf National Time 7000 (which looks like a cross between a 2001 and a Imgur: The magic of the Internet Mirtone 790).
The Imgur: The magic of the Internet Edwards 1526 and Imgur: The magic of the Internet Mirtone 70707 also have much in common. One of these panels’ most distinctive features is the fact that the board is mounted to the door rather than to the backbox; this feature can be seen in these interior views of the Imgur: The magic of the Internet 1526 and Imgur: The magic of the Internet 70707. While Mirtone was acquired by General Signal in 1988 (and started rebranding Edwards products shortly thereafter), both the 70707 and 1526 appear to be from the 1970s; it is therefore unlikely that one of these panels is a rebrand of the other.
As for signals, here are a few devices with noticeable similarities:
- https://www.ebay.com/itm/Edwards-Adaptahorn-Fire-Horn-364-A-10v-3-Amp-Vintage/352631354993?hash=item521a777671:g:LDMAAOSwI2xbYI14 Edwards 300-series Adaptahorn and https://www.ebay.com/itm/Vintage-Audible-Signal-Fire-Alarm-Type-411-National-Time-Signal-Corp-w-o-plate/153785778589?hash=item23ce58c19d:g:KVUAAOxylpNTV-mc National Time 411
- Imgur: The magic of the Internet Edwards Adaptabel and Autocall Depend-A-Bell (the Depend-A-Bell in this photo is rebranded by Pyrotronics)
- Faraday 5640 and Amseco BZ-50
Finally, while these are not fire alarm devices per se, the mounting plates from the Wheelock AS and Faraday 2884/Siemens U-MMT are suspiciously similar (U-MMT plate at the left, AS plate at the right):
