I love searching these forums…Never resolved but I’m going with 1979.
Maybe 77.
Definitely a model from the 70’s, but how were you able to pinpoint a year?
You’re not able to. This company went out of business many years ago. I’ve come across a few out of thousands and thousands of inspections. I’ve researched the inter webs many times for long periods. Never was able to find any information about serial #'s and age. All you are doing is guessing. Best to say in your report the water heater is at least 25+ years old (likely older) and past its expected useful life.
Why guess at the exact age? From what information I can obtain they went out of business in the mid 1980’s.