hi my work is in the film industry  so myspace is most likey not suited for this forum i bought the barrels from 
www.marstar.ca they do not need to be plugged they do not sell barrels plugged i never heard of this they are great barrels , i was thinking of makeing a black powder gun  , putting the barrel in the lath  makeing also a breach plug  anyway i put a link in of fotos of these items the zb37, barrels, and some other items i did not yet photograph the spade grips  or retraction units or barrel supports click here 
http://picasaweb.google.com/lh/sredi...xYw&feat=email if of interest i can put more into this album cheers john MUSKET SOURCE 
http://www.militaryheritage.com/muskets.htm