Ian,
I recently been down the same path with tyres for Minnie. I went with the Falkens and so far, they're good. Only done about 1000 mile on them so far and all good. Hangs on on corners in the dry - mind you I've only got an 850 so no power machine

. Haven't tried them in the wet.
I got mine at Bob Jane but Tyrepower also can get them. Back in Sept, they were $110 but I think they went up at about the same time to around $120.
One thing you may want to decide on is whether you want to fit them tubeless or tubed. They are designed to be tubeless I believe. However, when I checked with Bob Jane before fitment, they wanted to see the rims as they thought that being a 1963 model, they wouldn't be "safety rims" with the extra lip on them to hold the tyre in place. They were right and my rims do not have the extra lip so they wanted to fit them tubed.
When I got Minnie, it had tubeless tyres on it (Dunlop aquajets) and in the BMC manual, they list the tyres as tubeless. From what I understand, if you fit tubes to tubeless tyres, you may find the tubes chafe against the rough surface of the tyre and get holes in them. I decided to go tubeless and the Manager at the Bob Jane store wanted a copy of the BMC manual pages stating the tyres where tubeless before he'd fit them. I gave him a copy and all good.
At the time I was after tyres, I posted the question on this forum and got some terrific responses about tubed and tubeless. Not sure how to post a link but maybe if you searched you'd find the thread.
The common advise then was to make sure tyre pressures were maintained as the risk of rolling a tyre off the rim was higher when the tyres were low pressure or going flat.
Cheers, Rocky