Mettlen...-what you'll get is a chap, (or chap-ess!) from your local DVLA office, who will come and 'inspect' your saracen, and make a note of it's engine and chassis number. From this they will issue you with an age-related Reg. No., mine is 225XUF, although, purely from a 'looks' point of view, I've rather naughtily spaced my number out as per Military Spacing i.e. 22 5X UF, any coppers I've come into contact with have turned a blind eye to this, slightly naughty practice. The DVLA man, and I, could not find any signs of a chassis number, so I was permitted to use the Army No. of my saracen as it's chassis no. -83 BA 78. They don't even need to see it running or driving etc, to issue you any Reg No..... all a little surreal, actually....:-D