Auto Ordnance on the left, GI on the right. Stocks used by Chiappa for their M1-22 and M1-9 carbine replicas have the same issue. The new Inland Mfg uses the same source for stocks as AO but cuts a 1/4 moon shape out of the the front of the opening to allow a sling to go thru.
Attachment 77018
Attachment 77019