I can only think of a couple of people I'd trust to weld in a cage for me too.
Not sure what they're like generally but a friend of mine had a custom cage put in his mk2 race car and it didn't fit properly at all. Having paid extra to have the ends finished properly so it should have just been a case of welding it in, they all had to be redone so they fitted properly.

sunny - here's some more pics mate..
https://passionford.com/forum/viewtopic.php?t=126711
really should update that thread but i never get round to it!