Hi - 2 old Johnson outboards that have been in the cottage shed for years, pretty sure they're 2.5 hp, 2 cylinder about 50's vintage. The only no's I can find are SER 66742 M9D HD-25. I've got a pic but don't know how to post - if someone gives me their address - I can send pic. Can anyone tell the age of these from the no's. One works OK, the other is missing recoil mech. Are these worth anything? What's the correct fuel/oil ratio? Thanks...