Hi Z,
Get a carter to pick it up. You may find a specialist who will handle the whole operation, or you could organise it yourself. This could mean crating it or palletising it. The more that your dad does to prepare it the cheaper it will be. The local Harley dealer might crate it at a price using a crate from a machine they have sold as they probably scrap these. Paperwork would have to be sorted and the advice of a shipping agent could be useful, although not essential. Insurance on the other hand, is.
Ride it. Join the AA or RAC, the Harley Owners Group or other such club, arrange insurance (classic) and an Mot at your local station, fly out there and after checking the bike for safety and fitness for the journey home, head North. If you are travelling to a pre-arranged MOT, you don't need road tax and you may ride without a current certificate. This may not be strictly legal. The motoring org. will help if you break down, as may members of the HOG or other specialist club. "Break" it so they can't fix it and are required to bring it "home" as per cover.
If you do ride it, check oil levels (engine, gearbox and primary drive) before you ride it and at very frequent intervals thereafter, 'till you have an idea of oil consumption which, because of a thirst not experienced in modern machinery due to a combination of oil leaks and general consumption, could surprise you. This could be as high as 100 or less miles per pint and probably no better than 300 or 400 mpp at best depending on engine condition (and leaks). Don't wear your best, most flambuoyantly coloured leathers, and be prepared to be very afraid at the clatter that the engine makes relative to what you are used to
If all this seems too much trouble, give it to me
and I will get it home.
Everybody raves about the "heavyweight twins" and rates the "Sporty" a "girls bike" but personally, I like the Sportster because it can be made to corner and stop.
Good luck to you and safe home.
A.