There's a garage in Lowestoft that specialises in BMW and German marques, they might be worth giving a call.
BUT I have never used them personally, so it's not a recommendation, I'm just highlighting a garage within a reasonable distance that has probably seen one of these before!
https://cypressautoservices-boschauto.co.uk/
They also used to do trailer hire, so possibly "2 birds..."
If it ends up back in your drive, I'm happy to pop over and stick my camera in the plug holes to confirm pistons are unmarked.
Could also possibly borrow Steve's Landy to tow a trailer if need be.
Thank you for your reply, I’ll ask Allan to give them a ring