But surely as he has half of a number plate the implication is it's already been registered?

The '28 basket case I bought ages ago was like that, no v5, no reg number but known to have been on the road before.

I went to my local DVLA office with the frame number and they found it on the system.
You need some luck here and a patient DVLA employee as the format for frame numbers isn't fixed;
It might be mc21 123456, or mc21-123456 or mc21123456.

That is of course in the UK.
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