Hi Paul,
You don't give your location, but if in the UK, using this frame to put a bike back on the road shouldn't be a problem - although it may have to be with an age related number. If you join the LDMCC, when you are ready to put the bike on the road, you will be able to get a dating certificate from the registrar. This will make dealings with the DVLA much more straight forward. A couple of years ago, I registered a special built mainly from Douglas parts, and the whole process at the DVLA took less than 15 minutes - but I had to cough up the fee of £50 for the 'new' age related number.
Regards,
Eddie.