Assault line style Tank bracket cage. Looks like it was cut off stock? Nicely cut channel. Looks like it was taken off a stock and then nicely machined. Could be attached to a WGP bar stock (T or L or loop). Channel thichness on top for milled channel is .5 inches, and width between 2 holes (center to center) is 2.6 inches. And end to end of holes is 2.975 inches. Has 2 of 4 thumb screws and has various dings. I would polish off 4 weld marks on side of channel and use it on a sniper 1 with WGP T stock.
After a closer look at this cage here are the modifications I would recommend to ready this for attaching to a wire stock.
Mods on the Cage:
1. File area for recessed Y head screws from the top of cage side so that the holes allow the heads of the screw to be recessed while still attaching in a sturdy manner.
2. File the weld marks that protrude up from the channel to get the wire stock to attached without the sides being too tight.
Mods on the stock:
1. Drilled and tap two holes for the screws in the stock.