There are sufficient points if you show you have used all of the parts other than the engine.
Rear axle (Diff, drive shafts, brakes), gearbox, front hubs etc and Steering column all count. You then get five points for a new chassis.
The DVLA wanted proof they were all from the same source and that the chassis was new.
I took them build photo's of the donor being dismantled, the bits being assembled onto the new chassis, Photo's of the chassis being built and receipts for the steel. They took seven weeks to decide but this was their decision to issue, I told them I wasn't that bothered, really.