Right, got some more info from the seller.
I questioned him on the private reg (is he in the process of getting it removed and if so, was it via the DVLA or Post Office to give a timescale) This is the response -
I just want to hold onto the log book to show it to the new owner as point of seeing the car to see so as they can see it in person not just a picture taken and then move from there, They have said that I have to fill in a V317 form in which I have now printed just in case and send them the original log book off still in my name to get the plate transferreed which they are saying takes 2 weeks along with the MOT and a copy of the tax disc, once it arrives back I then send it back to them again with your details and I am happy to print a reciept stating ownership and supply copies of all paperwork but they are saying you are welcome to take and use legally while it happens so long as insured on the private plate until the new one is issues.
Hmm... so I drive it away with his plates on then, from a specific date, the plates no longer apply and I put the old ones on? Surely that means that he also looses his set of plates from me unless I mail them back?
Never dealt with anything with a private reg but this strikes me as a bit odd. Also, I've googled this situation and is seems to bring up scare stories mainly for the seller. Guys buying the car and, seeing the reg belongs to the car, the new owner owns that reg.
Of course, google is a pit for negativity so this may just be scare stories.
Your opinion please folks. Seems more of a risk to him than it does to me.