Looks like no one has found the age yet.
You should be able to tell if its older than 10 years just by looking at the logo/labeling on it.
Simply recommend replacement on these when older than 10 years.
Client just called me and said they wish they had took my advice, their 10 year old water heater just started leaking.
I don’t defer many things to contractors, I simply make the decision as I’m being paid to do. If you can’t make a decision in this business, the agents favorite driveby contractor will be available to say its ok and collect his $60 driveby fee from the agent.
An agent told me once that that she tells buyer’s to ignore everything in an inspection report where it appears the inspector had no true opinion since all reports she has seen over the years are basically soft and inconclusive. I told her that she would either love or hate mine depending on her loyalty to the buyer.