yes you are 99.999999999% correct 3.8 litre E type
It was difficult to take pictures - 1715 or 171 and some scratch - may be?
And - my chassis mounting bracket has been modified - I understand, but why the hole ?
Maybe someone has used a mounting bracket (or part of one) from a later Jag? I seem to remember XJ6 had a spring arrangement there, with a pin coming down from the gearbox? I’m sure someone will know for sure.
Thank you very much for your advices, it is a big help for me.