Hi I've had my logbook sent back three times now by DVLA I have two motorcycles both in my name one was brought as I doner bike I want to swap the engine over on one which is just a rolling chassis they are bike from the eighties I've have owned theses for about 10 years now And DVLA wont change the engine number what can I do to resolve this issue as I dont want to have to take the engine back out as I want to put it on the road any help would be much appreciated