47 year old old steam boiler

The photos attached show rust on the outside boiler. what does this indicate?

Howard, look at the origin of the rust stains, it is likely from a stem vent or pressure gauge on top. In my area I see boilers that old, and older all the time, and that is likely surface rust and not a big deal.

Run the boiler and see if water comes out. What can happen:
-a steam boiler needs to be filled periodically (because the water escapes as steam)
-if its over filled (by accidental user error, or the fill valve begins to fail) water will exit the steam release at the top, looks kind of like an old school train whistle, but small.
-that water will rust the outside of the boiler.

Water may have been spilled there from a plumbing repair as well. Just make sure it runs for a bit and gets good and hot and no water leaks out now.

PS fill in your profile in the control panel so others can see where you are it may help in answering questions.

Thank you Mike

The owner did inform me the TPRV did leak last year and was replaced. During the inspection I observed a small leak from the fill tube glass indicator. It requires a seal replacement.