Another Luxaire Furnace age question

This doesnt follow the normal SN codes that I see in order to get an age. Any suggestions? Thanks!

“It’s old. Budget for replacement”.

Luxaire was sold/merged in 1980, so I suspect the date is “77”

Told ya!! :wink:

Anytime you see a metal data plate fastened with rivets, you can be sure it’s at least 30 years old.