Help identify Trench handguard

Is this real? There are no markings or sling swivel.

https://i.imgur.com/sifxFsF.jpg
https://i.imgur.com/n8frYUc.jpg
https://i.imgur.com/lO65Svw.jpg
https://i.imgur.com/bL3A3nd.jpg

thanks --- Kent

Need to see marks, if any on left side of adapter.

No marks what so ever.

It looks like a 6 row Winchester bayonet adapter

It's the type used on early WWII M97 trench guns with the U.S. receiver markings without the ordnance bomb. And they are generally seen with WB stock cartouches instead of the later GHD.

It looks exactly like the line drawing on page 26 on TM 9-1005-206-14P/2. Department of the Army Technical Manual dated November 1962 which is described as being for the Winchester Riot Type 12-gage shotgun M1912.