The Ariel Owners club is one of the best going - highly recommended to join. And Draganfly for all spares, if you don't already know that.
The Huntmaster used a slightly modified BSA A10 650cc engine from the start, with Ariel everything else.

Scott now that was a wounderuse machine, the much later Silk engine had a lot of Scott about it.

The Bern wrote: ↑Tue Jul 24, 2018 12:12 pm Remember those will both have cast iron valve seats bud, you'll need some 'octane improver' will most likely run after a good spray of electrical cleaner on the contact breakers

The last thing you will need is octane improver! These things were designed to run on the dreaded post-war 'pool' petrol....
And don't believe the old wives tales about valve seat recession - it was scaremongering at best; and with the limited miles these old bikes do, it's never going to be a problem.

Other thoughts...after 30+ years, both magnetos (and dynamos) are likely to be dead - just because a plug will spark in the open air, it doesn't mean it will spark under pressure in the cylinder.
If the fuel stinks, the carburretor jets may be gummed up.
The fuel lines, oils, greases, brake shoes, tyres, tubes, control cables and wiring will almost certainly need replacing.

As you can probably tell - I've been there..!

But good luck - and do please join the AOMCC and tell them you have them? Can't see the photos, btw.

Fuel system is bound to be gummed up they have monoblocks on them so the carbs must have been changed,
I have dealt with Dragonfly before good people, I had a VB and a swinging arm Red Hunter what I do is put a
small amount of 2T oil in with the fuel and have run many older bikes for thousands of miles with no problems.
I cant decide to join the Ariel club or VMCC we have a very active local group and I was a member of the Morini
club up to last year.
Don't know why you cant see the pics others seem to be able to and I can so I am not sure.

Yes I use a bit of 2T oil as well in non-catalyst bikes- seems to do a good job!