If one was possibly going to re-shell ones spangly mechanical bits in a williams shell how is the registration of the vehicle/s affected?

Basically planning to put my 16v bits on to a tidy willy shell. I tried asking teh DVLA but they were totally inept and useless.

So could L588 be re-assigned a new chassis no. without going on a Q-plate?

or

Would it get the new chassis no. but have to go on a Q

or

Could the donor williams be re-registered as a 1.8 16v?

Don't want to end up paying williams insurance for what will amount to a 16v without a sunroof.