there are two Allen keys in the middle, what size are they,
I assume that you mean the two central 5/16" socket nuts? So I would think they are a normal 7/32" key size (not 100% sure however).
what torque setting are they,
5/16" head fasteners = 16 ft/lb
3/8" head fasteners = 18 ft/lb
and I can't seem to find a snap on Allen key to fit the torque wrench! Any advice?
Generally square drive Allen socket attachments come as part of a set, but you may be able to buy a single item from a good tool shop?
If you cannot find one or you don't want a set, then you could buy a normal cheap single 7/32" allen key (if that is the right size? Perhaps TBS will know?) and then cut a length off of it and insert it in the socket nut, then use a normal 7/32" hexagon socket to turn it?
