Got on the mill today and drilled and tapped the 8 x 8BA holes. Very time consuming, mainly as they are blind holes and keep withdrawing the tap and clearing the hole.
Think I had to do 4 runs with the tap, clearing the hole each time before hitting the bottom. Being so small I started the thread with a taper tap and got at least half way before switching to a plug tap.

The 4BA location pin hole was also done, no issues and pretty straightforward.

Here are pictures of it up on the machine, packed out with leather to protect the casting although getting the whole thing square and level was a challenge to say the least as the casting was a bit wonky.

I haven't bonded the turret to the tube yet but have fitted it up to get a good idea of how it's looking. Also need to grease and fit the springs and plunger's.

Really close now, very happy with the results so far.

Attachment 103254Attachment 103253Attachment 103255