Sears Homart

Can anyone tell me the age of this unit from todays inspection? I can not find any info, Thanks

Model# 867.6621 H-Q
There is no Serial#

I would need the serial number, but I believe the Homarts are from the 1960s and possibly into the early to mid-1970s.

Have it inspected thoroughly by a heating company. Each and every one of these models that I have been dispatched on in the last 5 years have cracked heat exchangers.