this is what OP's talking about. theres not much too it, you could make your own from a bayonet using a angle grinder / sawsall. look at the butt of the bayonet, where I circled it in red. you simply cut the bayonet grip to the correct length, trim the grip metal to fit thru the end cap, then peen it flat. easy peasy. if you use a older bayonet like pictured you can get one for around $30.00
Quoted: this is what OP's talking about. theres not much too it, you could make your own from a bayonet using a angle grinder / sawsall. look at the butt of the bayonet, where I circled it in red. you simply cut the bayonet grip to the correct length, trim the grip metal to fit thru the end cap, then peen it flat. easy peasy. if you use a older bayonet like pictured you can get one for around $30.00