I would consider attaching several ArtDivs to a spare Army HQ or an airborne corps up by Moscow, and using this massed artillery (3-6 ArtDivs) on as-needed basis for attacks up there. With two sapper regiments per rifle corps and 3-6 ArtDivs, almost nothing will be able to hold against you.
Frankly, his defensive CVs near Moscow look positively puny, I was regularly facing CVs of 60, 80, even more than 100.
I would definitely start attacking with a view to (i) ramping up the war of attrition and (ii) forcing him to pull back (and thus abandon fortifications). If you let him sit still too long and dig in, you will find it VERY difficult to dislodge him later on, this is what happened to me.
EDIT: Another thing, personally, I would try to avoid any overly-ambitious offensive plans at this point, as they probably won't work, as I don't think your forces are strong enough to maintain a sustained offensive if he can focus his reserves. And why not leave those Axis allies hanging out there past Stalingrad, attacking there might only encourage him to shorten his lines, which I'm not sure is what you want at this point.
< Message edited by 76mm -- 5/8/2012 8:16:06 AM >