Negative tagless and it has 123ABC as serial. I believe I got an ATL
Most likely. A good percentage of APX radios without tags and/or phony tags are either stolen, ALT (Accelerated Life Testing=abused and battered, literally) or DEV (development) radios that are either being sold by those who know what they have and fail to disclose the provenance, or surplus brokers who are clueless.
It is up to the BUYER to ask questions, request history, and select a seller who stands behind their items.
Not all tagless radios are junk, some that have been vetted by reputable sellers aren't suspect, but don't expect Motorola to support a third party purchase of an aftermarket sale anymore than Ford or GM would warranty a vehicle made from aftermarket parts with a salvage/questionable title that was say, in a flood or totaled by an insurer.
Always buy the SELLER not the item.
Good luck.