It has taken a while to make, have been doing them (3sets) in my spare time, along with the H165 and H190 lsd's. Looking forward to putting in the car

To put things in perspective, I think our friend Mr Topgear is more than an assistant in a blacksmith shop who makes these things with a hacksaw & a bastard file.

Methinks that there is a deep involvement with a very well equiped engineering facility that does this type of thing as part of it's mainstream business.
In fact, I suspect that it is probably a well known, & possibly a nationally known business that turns out very high quality, precision engineered components.
Hell, we know about this place in little ol' here, so it has a good reputation.

Am I close?