Ruud Oil fired furnace age?

Serial# HJ114 F3277 5187

Ruud is a division of Rheem. Look at Rheem style 2:

It’s 1977

Also, whenever you see a metal data plate and can’t find any info, you can assume its past the manufacturers suggested service life.

Thank You, Home was built in 1978, so I assumed it was at least that old.