Can anyone machine this for me?

[haitch]

I think you'll struggle to drill the focuser plate as neat as you'd like.

The lump of metal is on your last photo where you are inserting the new focuser drawtube in the old. Between the drawtube and the base of the focuser there is the underside of the collimating ring that will protrude through the tube so the tube will have to be cut for that I think.

I've got to finish fillering the walls of a bedroom now before I lose the light completely but I'll try and take a photo later on to show you my single speed skywatcher fitted to a non-skywatcher tube as it has a similar, but squarer, lump.

[yesyes]

Thanks for pointing that out, haitch. I just had a quick look at the bottom of the new focuser and I now see what you mean. No idea why I hadn't noticed that before.

That means the focuser is definitely going back for a refund.

Back to square one....

[haitch]

Glad you got the jist... couldn't get a good enough shot of it with my iphone as it's flocked and very black inside.