You will need to start the Tax pretty much within a few weeks of the applications , as it free don't worry to much about it but without the road tax they wont issue a reg r log book. If its been in GB historically then you should not need a nova only proof of age and if you have the old log book that really helps. I had had to register a number of classic bikes over the years and 2 being Indian's. They where both imported from the USA in the 1940 so no NOVA needed for them just the proof of age from the VMCC. and insurance and MOT. Now the MOT has been lifted for over 40 year old vehicles that's removes that problems. Its was a lot easier when you had local DVLA offices you could go to and talk to a human. Hope this helps.