Sutherland Target Sight - Eyepiece Thread Dimensions

I just purchased this Sutherland target sight for my Ross Mk II** restoration project. More on that later. I have yet to receive the sight, but need to source an eye cup for it. Could someone please tell me what the thread diameter and pitch are and, perhaps, what other makes take the same thread? I feel especially fortunate that the cover is included.
As always, any and all assistance is much appreciated.
https://www.milsurps.com/images/impo...0/sn2yoi-1.jpg
https://www.milsurps.com/images/impo...0/ilgd3o-1.jpg

The cover is a very rare item.

That might explain why I had no idea such a thing existed :D

I have a Canadian Tool & Specialty aight on my Commercial target. I would like to also know the thread dimensions, as I want to use a multi aperture eyepiece for target use.

I assume this is on that nice Mk II** you recently acquired.
I did determine the thread specs and ended up making an eye cup. This is a good test of my record keeping, and I give myself an F. My notes indicate it appeared to be a # 12 x 28, but there is no entry to confirm or correct that. Good sign?? If it turns out not to be a # 12 x 28, I will measure the eye cup, but will likely not be able to do it before the middle of the month.

Confirmed - it is #12 x 28 (#12 NF).

Get the picture of one in your mind and keep rummaging through parts boxes at the shows. If you want to really try, show photos around the tables and ask.

It would likely also be a good idea to drill and tap a small piece of metal for #12 x 28 to act as a thread gauge.