My experience has been to not get overly concerned with originality or completeness for any car you are going to rebuild from the frame up.
My S2 was bought more for having a Cross-Flow engine on Webers than it's alleged "Just a little TLC needed" condition.
In theory it needed little having been put away as a running car.
Theory and practice often differ.
I am finally beginning to reassemble, after not only being down to the bare frame but also repairing it as well.
My '68 El Camino "Ran" and drove when purchased but was rusty around the wheel wells front and rear.
Once I began to restore/upgrade it I find that the only original pieces on completion will be the main body cab, doors, and some trim pieces.
Engine, trans, rear suspension, front suspension, chassis, windscreen, gauges, seating, forward sheet metal, rear 1/4's sheetmetal, wheels, and sundry other bits all replaced.
My Lotus is actually the simpler build!
To be fair a lot of this due to my insistence on having a unique vehicle on completion.
Point is that if you are doing a full restoration a lot of the original parts present may be replaced anyway.
So you may want to make an offer on that slightly buggered TC on feeBay?
If the body is not full of old poor repairs it seems a decent start for a full restoration.
Shipping to the UK may be insane however, and I expect import duty may be punishing?