A steady SRS light on the '86 does not necessarily mean the air bag is bad.
Any of the components could be. You say "Salvaged Title", could mean it had been in a wreck and repaired, possibly a wreck bad enough to deploy the air bag. Same thing with my 560 and the thrown drive shaft, blew the bag and when I changed the bag and crash sensor I still had a steady SRS light. A little tracking showed that the ETR's (seat belt tensioners) had also blown. They blow at a stage one crash, the bag at a stage two.
Another thing that can give a steady SRS light has nothing to do with the SRS system. Check the voltage output. If voltage drops below 10.1dcV the SRS lamp will come on.
EDIT: Just reread the original post and now see it was a stolen recovery. Was the bag stolen? If so, replacing the bag should douse the SRS lamp.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.