Terry,
Hope my comments didn't offend you. I've always owned Hondas but I also admire fine British bikes. We are very close to where you live and maybe sometime could get together to see each others "toys". (I also am familiar with Peferlaw, and think it's a lovely place.)
I really am not aware of any Vintage Japanese clubs in this area. I don't think there are any. The only vintage sort of club active in these parts is the CVMG, but maybe that's the "regular Vintage club" to which you were referring. I have seen a number of like-minded SOHC-4 750 riders who rode in together at local cruise nights, but I don't think they actually were part of any club. There is the Vintage Japanese Motorcycle Club (VJMC) and they have a very nice newsletter, but no active chapter in this area that I'm aware of. However, there seems to be a lot of nice folks on this forum who are even in this area...so maybe we should get something going when the riding season comes 'round again.