Not the most obvious choice for a conversion. An Uncle of mine, long since departed, had a P5B, lovely motor.
https://www.ebay.co.uk/itm/Apollo-1969-Rover-P5B-Coupe-3-5-V8-Auto-Period-Camper-Conversion-Unique-Classic/164292038767?hash=item264091906f:g:~DIAAOSwrHNeroqG