Keep it in your home part of the RV. Unless you show off and tell you have a piece how else would lEO know?
If he has to use it EVERYBODY will know. The NRA publishes a booked entitled something like "Gun Laws in all 50 States". It might also be available on line. I'd suggest you pick up a copy if you plan on carrying while traveling over state lines. However, I strongly suggest you don't carry in NY or MA unless you are prepared to suffer the consequences. I would also recommend having a lawyer on retainer and all his/her contact numbers just in case.