Can someone ID this scope mount?

[Ukraine Train]

I got it at a garage sale for $2 but not sure what it's for. The holes line up with the pins in the receiver in my Mossy 500 but when you hold it up it appears that the front of the mount point up at an angle away from the barrel. It's made by B-Square.

 

[Ukraine Train]

bump

 

[Ukraine Train]

Someone's gotta know this. bump again

 

[Bruce626]

... with that up-angle it must be for the Mossy grenade launcher.