What are the DVLA rules for obtaining a new registration?

Am I right in thinking that any previously used parts have to be reconditioned and to an AS NEW state? or is there more to it?

You have to use all new parts, but they do allow you to use one donor part as long as it is reconditioned to "as new" condition, as you can show proof of this. For example you might have a new engine and gearbox which are not too tricky to source running thru a recon Sierra diff.

The cost can start to ramp up when you have to start using new parts for suspension uprights and hubs etc as most kits require these from a donor.

or you could use an '05 written off donor.