Legally mine is a pistol, therefore shorter than 16" barrels. The little knob on the back makes a good short stock though. I think it may be for steadying off the forearm when shooting. Never seen another stock like it so I don't know. It is great for hunting the bottoms where there is a lot of thick hedges to meander through.
Actually your rig wears a Fajen Big Shot grip with a Fajen Banana forend (both long discontinued). The grip was designed for a push/pull stance for stability using both hands on the grip, and they were available for either right and left hand shooters. You push with the shooting hand, pull the "D" back with the off hand IOW. Worked surprisingly well, which is good I guess as they are ugly as sin IMO. My last B.S. set was their Victory color (red, white and blue), which was even uglier than your coffee set. They also came in pepper and camo colors.
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Good looking shorty Dave. I really like it (as a long time fan of bullpups I like short carbines).
My last shorty Contender was built to be a predator hunting rig, used a Choate folding stock, Pachy forend and 18" 6X47 barrel. Made to be a great light weight rig to swing in tight cover. When I lived in the condo I carried it folded in a tennis racket bag so nobody knew it was a firearm. Picture was taken when first put together... soon changed the scope to a very compact 3-9 sniper model with lighted reticle.
BTW, keep in mind BATF minimum rifle length when building these rigs.