you will loose considerable value if you rip out the bathroom. It's in AMAZING shape and as mentioned looks fairly original. I wouldn't be surprised if the right buyer paid in the high teens for this - if you rip out the bath, i'd say you'd lose thousands of dollars in value... That, and there just aren't many all original
1964 airstreams. It would be a real shame if you ripped it out.
IF you want to have separate bathing facilities, why not sell this and buy a junker to fix up? I bet the sale price of this would cover your purchase and reno costs of a non-original / gutted vintage airstream.