thanks again guys. overdrive Services in UK seems to be marginally cheaper than VP in USA, which is surprising since the current Laycock Overdrive owners , is Gear Vendors in USA (almost 20 years I recall) . Ive assumed all the production equipment went there when laycock sold out to them …. Yes, ive found O rings locally.
I note VP dont list the later P type overdrive used in some 740's and 940's