I can't tell you that it's for a specific sight or scope, but there is a knurled knob that goes on that threaded cross screw to lock it in a certain elevation.
That's cool as heck! Would love to find one myself!

Given the apparent pivot point could this be a front mount for a tube sight?  I've been going to build a 30" or so long tube scope and try to mount the front on some sort of pivot.  If the rear mount were high enough one might need to raise the front for shorter range shooting. just a guess.  Very neat artifact.   

Dave

I like that mount, a lot. Very high quality and I would consider it a front mount if, it pivots on the large diameter area.

You can have both elevation and/or windgage on either end of the barrel with the same results and movement, based on the C to C distance of the mounts.

Not easy to make but, the setups are fairly straight forward with just a little hand fitting work.

Much easier than building action

Frank

Too bad he didn't have the front mount, as it probably was windage adjustable. My guess is the 360 degree movement aids in putting the scope and mounts on the gun, without removing the scope from the mounts. If it didn't pivot, there would be no way to put the mounts on without removing the scope first. Then you'd have to slide the scope through both mounts carefully once mounted.

Chuckster wrote on Dec 7^th, 2015 at 11:41am:


If this is a front mount, then the rear mount would need to be fairly tall to allow this mount to lower the front for longer range shots. As tall as this mount is, it would either be all the way down, or the rear quite tall to work.

Had lunch with a good friend who's an advanced antique scope collector. He asked if I would forward the pictures here, as he doesn't do any forums. I'll send them to him, and see what he might add.

Chuckster wrote on Dec 8^th, 2015 at 11:11am:


Going to get more complicated, but hopefully better Chuck. It has no vernier elevation adjustment, so I'm adding that, so it will be more user friendly at the range.

UtahDave wrote on Dec 8^th, 2015 at 7:34pm:


It's a 32" scope. One of the cheapo Tasco/Navy Arms that they sold decades ago. Picked up the scope and mounts at our local gun show recently for a  giveaway price. Had crooked crosshairs, and lenses a bit cloudy from dirt. Pulled it apart and cleaned the lenses, installed new crosshairs, and then stripped someone's black spray paint off it. Antiqued the outside to age it, and aged the mounts carefully with 500 grit emery paper. It needs another application of solution to get it a little darker. 
I have another that is on my Hepburn, but mounted in Winchester mounts. It needs a better rear mount to make it go past 200 yds. in the .45-70 Hepburn.
Here's the mounts:
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And my Hepburn with the Win mounts. Got this one much darker, and like  the look better.:
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