Custom Shop I think for the 3x. You can still find the M8's on ebay most of the time.
Jack here's the thing on No.1's: You need lots of eye relief and tube length, but it also depends a great deal on how you are built. If you have a short neck, you will almost certainly have a harder time finding a scope. I have found that I need and offset ring in order to use some scopes that others have great success with, that would include a 4x28 Leupold, an M8 3x and a VX3 1.5-5. With an offset they work fine. Without the offset, what I have had success with is a 3x36 Leupold, a Nikon Omega, an original Burris Fullfield 3-9 and some old Weavers. Also the 2-7 Leupold worked well up to about 5x.
So the bottom line from my experience: Try the 1.5-5 or 3x Leupold and be prepared to use an offset ring. Actually a 2.5 Leupold might work also, but I've not tried one.
YMMV.
