Thanks for the kind offer Brian I've not had any luck so far so I'll email you shortly... Had a look at Muskys links, thanks for that Musk... There are a lot of repro taps of this kind and I'd imagine they would be more leak proof as the seals have teflon rather than corks but somehow the repro taps look too 'new' for an old unrestored bike, might look okay on a concourse restoration though. I have found these sliding type taps to be better than the barrel type with corks but not so easy to replace the corks quickly if need be as they have to be completely dismantled.
LJ.