Hi Ian,
Looking at pic 1 in post
#174 , it doesn't look to me to be a suitable release bearing to use - the bearing thrust face should contact the pressure plate release fingers inboard of their tips, i.e. where the tips have a slight bend.
(look at where the original bearing contacted the release fingers on the 126? p.plate, post
#166 ).
What is the black contact ring on the latest release bearing made from? This release bearing reminds me of what was used on the earlier coil spring type pressure plate clutches.
Are there any maker's markings/numbers on the pressure plate which could be used to positively identify what it was designed to fit, determining this should then allow the correct release bearing to be identified.
When I worked at a Co. that relined brake shoes/ rebuilt clutch pressure plates/discs (summer job in the 1970's), they had catalogues detailing all parts, part numbers and dimensions (to identify the correct rebuild parts). Maybe try consulting a specialist Co. that rebuilds classic car clutches for advice?
I did try looking up INA, Fag, SKF bearings websites to try to get you the release bearing dimensions you were looking for earlier but was unable to do so without a bearing no.
In order to avoid further disappointment, I would urge you to continue looking for a release bearing compatible with your new pressure plate as I don't think what you intend using will be satisfactory.
Regards,
Al.