What I'd like to see ...

[d_Guy]

Also some early P&S  campfollowers could be handy.

I am in favor of anything that adds more civilians (including women and children) to the general period 1550 to 1700 in Europe.
Woodland Indians in the same period in NA would be good too. Oh...and Aztecs (or Mayans..or both!) 

[Sunray]

It might be cold weather gear wrapped up inside it

Looks like the M1949 Sleeping Bag (Mountain) -the Yanks had a surplus which they shared with all UN allies.  It was a good piece of kit (Still around in the  1970s) Some bright spark invented a stuff sack in the 1960s that reduced the bulk. You could get it unto the top of a Bergus ROC.