Michael has the right of it with regard to the barrel bands. The detent 
is a metal spring, formed into a right angle, with a notch in the end.

  http://galootcentral.com/components/cpgalbums/userpics/10072/Allin_08.jpg

On my exemplar, the barrel bands have screws; some did, some didn't.  
Also, wood on the exemplar is worn to the right, showing all of the 
ramrod. Originally, the taper to a smaller size would have been much 
more gradual.

Accuracy always changed with moisture variations. Soldiers oiled the 
heck out of their stock to keep it stable.  Please note in my picture 
how my new stock looks like walnut, but the exemplar is almost black. It 
too is walnut.  This was very common, and is due to oiling.  In most 
modern rifles that have wood stocks and accuracy is a major concern, 
they alter the rifle so that the barrel is 'free floating.'  You can 
wrap a piece of paper around the barrel and it will slide almost all the 
way to the receiver: the barrel is close to the stock but not touching.  
This relegated the stock from structural support to a mere handhold.

Gary Katsanis
Albion New York, USA