vlink55, You should have this moved to one of the following forums, General, Tech Issues or Class C. Your in the one for Technical Support issues like how to post pictures, or for posting test picts or messages.
No big deal.
Generally 16.5 are a little hard to find and I don't know where you are but if there is a Big"O" close go there or go to a truck shop or ask a real tire shop if they can order them. An 87 is kinda old and I know nothing about them but you can look tire and wheel size up on line. I just wonder if they came from the factory that way or not.
I'm not against older, classic type RVs, in fact I am looking for a mid sixties ford pick up and very small cab over camper. I'm just saying I am old but more familier with later RVs.