Although Henk used to provide a worldwide dating service, the UK DVLA have only ever accepted approved clubs located within the UK.
It's not always clear who is allowed to authenticate what as there are some very general clubs and museums on the list who may well have very little specific expertise, but you probably have a choice of the BSAOC, VMCC, IMPS or MVT if you're a member.
Thank you Guys, I am a member of IMPS so I will contact them once more. I did pay for it previously with IMPS but that was to authenticate an attempt to get my original number back. That failed and the dating certificate expired....who knew? Anyway, its always been registered on 498NAU which is a 1962 number allocated to Dawsons of Nottingham and I have tracked it sold at Ruddington to a month before registration, but in the absence of records its dead . Shame as I have always known it since we bought it as 498 NAU in 1975.