Don't bother -- they suck eggs. Despite what the box says, the Mutals do not have the Vam Buren soundtracks. I was majorly PO'd at the time -- I should have returned them to the store. The Keystone and Essanays have "bad jazz" soundtracks, with music repeated both on a short and across shorts ad infinitum. I turned the sound off.
For the First Nationals, they were additionally sabotaged since Totheroh used the C and D negatives for some (perhaps all) when Chaplin reissued them. I know that for THE CHAPLIN REVUE, the C and D negs were used for SHOULDER ARMS. This was mostly because they were in better shape and I think (without looking it up again) that's all Totheroh had.
A year or 2 ago I found what I believe to be the version using the A and B negs on youtube, probably issued by Pathe in the early 20s. Doing a side-by-side comparison, they were very different. A and B had the preferred takes, but each shot from a different camera. C and D were the second best takes. They always had 2 cameras running side-by-side. Keaton did the same, and there are 2 different versions of STEAMBOAT BILL, JR. out there.
I can't find that version of SHOULDER ARMS right now on youtube, but it is available on DVD. Since the original version is PD, I can admit I downloaded it and have it!
http://reelclassicdvd.com/silent_era.htmScroll down or search to find.
SHOULDER ARMS (1918) was Charlie Chaplin's three-reel gift to survivors of The Great War. The comedy was released to great acclaim and success shortly before Armistice and provided very welcome laughter, particularly to returning soldiers. Charlie plays a lowly private who finds himself in the trenches of France, where living conditions are hilariously horrendous. Some of the many highlights include Charlie trying to sleep in flooded quarters, spying as a tree (!) behind enemy lines and posing as a German officer in disguise. The edition presented here is the Pathe reissue from the early 20s and is markedly different (and arguably superior) in takes, camera angles and performances than the later reconstituted version presented in 1959's THE CHAPLIN REVUE.