Hi Mark,
Hmm, I think it will depend on the offset of the wire wheels, plus of course the tyre width. But as they are sold for modern conversions I'd expect Moss to have that covered with a combination of adapter & wheel.
I know the sort of thing you're considering, in fact I had a similar set-up on one of my first cars - a Marcos - which came with 60s wire wheels. Personally I never liked them, the bolt on adapters were just something else to look after and cleaning the wires was a pain. But I'm admittedly lazy plus I used the car daily, so these days on a hobby car, yeah, I can see the attraction.
Brian