Help Identifying Mystery Body

[dano_____]

So I picked up this mag in Puerto Rico. I don't recognize it as any body I have ever seen. It is rough, but appears like it was professionally milled. The dual detents makes me think it isn't from a slug body. Ignore the rail, it was definitely done by someone at home trying to match the body. Thanks everybody for any help!

[alpha_q_up23]

seen that on ebay a while back, was hesitant to buy it because i wasn't sure what it was but it piqued my interest, glad to see some better pictures of it up close
most likely its a milled slug body, the dual detents could be an added detent by whoever machined it, glad someone's putting it to use