Date code for GE air conditioner

Specific Inspection Topics Inspecting HVAC Systems
1

Need some help on this one. My go to sources aren’t listing this one. Home was built in 1980, furnace is a Lennox replaced in 1993.

GE air conditioner
Model BTB724A100A0
Serial 253293109

GE AC.jpg
GE AC.jpg800×600 46.3 KB

Thanks

2

81, 91, or 2001.