The bank probably will refuse to reissue the check before 90 days.
It's not RV-related, but I am involved in a similar snafu involving a cashier's check that was lost by USPS. I know it was mailed because I was the one who mailed it. Tracking data shows its whereabouts until January 20th.... and then nothing.
The whole point of a cashier's check is that it is like cash. Mailing one is like mailing a wad of $100 bills. The bank won't give you your $100 bills back if the PO loses them.
The difference, of course, is that IF nobody cashes it within 90 days, THEN you can get your money back.
I deeply regret agreeing to mail that thing. There were, of course, extenuating circumstances.
If the check does not show up, and his lienholder is in the US, I'd advise your friend to wire the money instead, after the 90 days.
As for whether you should go camping in the RV, I'd get the guy to register it, etc., and then go to a lawyer with him, get the lawyer to advise him on what to write up in case of his death/coma/etc. An affidavit, or a will leaving the RV to you, or something. Then go camping!
