Downloaded and printed both these and the 82nd airborne. The 41st heads are too small as scaled default. They'll need to be scaled up by about 15% or so. If you happen to have both sets then it's really easy to import one of the 82nd heads and match the measurements with it.
The arms do swap just fine in terms of sscale. As do some Bolt Action arms. I have a couple of USMC arms on these guys. They're the ones with the rolled up sleeves.
