Bantam,
Congratulations for the great find! Very special car.
Regarding the rear flares, I think there is something confusing about this subject...
Somewhere on this thread, it is said that the rear flares were fitted right on the beginning of this car's life...
Observing their shape on the picture you posted right on the beginning, they look a bit like RS 2.7 shape or near SC's shape.
Around 69-70 the only available shape allowed to fit this cars were the ST type, as shown on the homologation form - I assume you are restoring this car under FIA spec's has it used to be earlier on.
Nowadays, it is the only allowed shape for rear flares accepted for SWB's on FIA events.
I am not sure, but I also think that by that time, (when you said the flares were fitted), the RS style flares were not available... (???)
I am also building a TR recreation from a matching number 68 T that "suffered" an upgrade very similar to yours...
Attachment 203478
and the rear flares actually allowed on FIA events, together with the stock ones, are those on this very well known car:
Attachment 203480
... which, in my humble opinion, don't really look like yours...
Maybe yours were custom made by some skilled guy at that time... ???