@JN - Thanks omae! I thought it was something similar - may end up using it for a character I have in mind.
Looking at the numbers, I think it should be RC 5, though I listed 6.
The sling and foregrip stack, but the powered folding stock is nullified by the sling (which is how I listed it). However, as this is a long gun that typically has a fixed stock, I believe that there's a "built in" point of recoil comp from the rigid stock, so the sling shouldn't count, either.
Of course, if that is the case, that means that you could totally lose the powered folding stock and just have it on the sling.
Either way, put a long coat over it with the stock folded and the sling cinched and you're at -10 Concealment.
-Jn-
Ifriti Sophist