Hi All, Thanks for your help. I'm sorted. I put classic car keys into e-bay and found two sellers Yorkscavr and Swampys-old-skool, both these guys know their keys inside out and have located the right blank for me, so I bought one from each.
I guess there may be different key shapes from the same lock supplier, but mine is a February '73 built car (although not registered until December '73!) and the chassis number is 73021165L , it has the GT6 steering column with the column switch and a WASO barrel/lock/key. The WASO reference for the key is WAS1 or FR, the key that the Lotus Specialist supplied me was WAS1R where the R seems to stand for Reversed as the 'ward' (i.e. the grooves down the length of the key) pattern is mirrored or reversed. Both the e-bay specialists told me without prompting that the FR or WAS1 is correct for the late +2's.
So, I know know a lot more about ignition keys and the terms used in keys/locks!! Every day is a school day
, plus I should soon have a spare key for my car (It cost about £5 by the way).
Thanks again all, Jonathan