Here is a lot of information on the family of steering racks from which the Europa borrows, in case it interests you (
https://www.macleansbridge.com/index.php/triumph-info/technical-information/22-steering-racks). Unfortunately, it doesn't directly address the Europa.
When I rebuilt my steering rack, I basically took a used Spitfire rack and added the Europa bits on to it - the rack tube extension, the tie rods, and the tie rod "cap nuts" (I think those were the only different parts). As I remember, the tie rods for the Spitfire were shorter than the Europa tie rods. The S1/S2 workshop manual has a page that calls out the different lengths of different sections of the rack (
http://lotus-europa.com/manuals/s2work/h/s2h.pdf). The steering rack section of the TC Workshop Supplement merely refers back to the S1/S22 manual and I'm not sure if the dimensions are consistent between the S1/S2 and TC since there are other differences that aren't noted but it might be a place to start when deciding what length you want if that's a question.
I would advise you to take the force needed to move the tie rods, as spelled out in the manual, seriously. Use a spring scale. Originally, I thought that loose was better as long as there was no slop between the tie rod and the rack. That turned out to be a mistake. I ended up using red Loctite on the tie rod "cap nuts" since heat was required to disassemble mine.
