Originally posted by Keef
The Weaver rail is nothing like a dovetail, totally different profile and size.
If you fancy trying to make one from scratch the dimensions are at

http://www.biggerhammer.net/picatinny/

The US Army calls then Picatinny rails but they are essentially the same.

There are normally two configurations for the mount. The most common uses a clamping screw throgh the mount that has a square section in the centre portion. This square sits in the slots in the rail. The second which is used on the B Square mounts is a central peg that is reversable so that it can be engaged in a slot or reversed so that the mount is not secured in the slot.

I have an NS 156 mount in at the moment and it definitely does not have a weaver/picatinny rail on it. I also have a Kite mount in and neither does that.
You haven't time to waste on here young man - get back to the workshop and get my mount made !