I used to do CW reenactments back in the late 80's.
Back then, it depended on the group. Some were "thread counters", they didn't like clothing that was sewn on a machine (stitches were too even, and the "wrong" number of stitches per inch, or the weave of the cloth was "too modern" as in "That weave wasn't used before 1870 ...) and other details that were "incorrect" for the 1860 to 1865 time period, that the audience didn't know, nor care about.
I was at one large event in Illinois. One of the people involved in putting on the event tried to run a guy off because he had a Remington Zouave rifle, which the guy claimed "was never issued or used during the war!" The guy with that rifle was part of a New York unit. He showed the ... "know it all fool" at the gate a black n white photo of his 3rd or 4th great grand father, in uniform, taken in 1864, who was a member of the New York unit the guy was portraying. His 3rd or 4th great grandfather (he knew which, I forget) was issued a Zouave. The very one the guy at the gate didn't want on "his" battlefield! (the reenactor's persona at the events he participated in was his ancestor.)
Most times, it didn't matter, as long as it looked like it could have been there. Union was stricter than Confederate, of course - everyone was issued a uniform, arms, leather accessories, etc, so those had to pretty much match. Some leeway was given on arms, since at the time, troops could (and did) buy their own. The side arm in one platoon could be a 1851 Colt Navy or or an 1860 Colt Army or Navy (difference between the Navy and Army was caliber. Navy a ".36" (cylinder was .38) Army was a ".44" (cylinder around .454 to .458) or an 1858 Remington "New Army" or the smaller Navy version. (same caliber as the Colts, but if conicals were used instead of a round ball, there was a significant difference between the Colt and Remington conicals. There were several different rifles used, not all the same caliber, ranging from the .44 Henry rim fire (never an issue arm, but enough companies/platoons/individuals bought one, the Union Government did issue the ammo for them., .54 caliber, .577, .58, The Burnside breechloading cartridge fired by a standard musket cap that was external from the cartridge, the Maynerd cap roll, (identical to what the cap gun of your youth used) To say the quartermasters had a difficult time would be an understatement.
Confederates were not issued anywhere near the amount of gear the Union issued. A lot of Confederates were never even issued a gun! They used what they brought with them from home. (hence my .45 caliber "Kentucky Rifle" was "historically accurate" for a Confederate troop. (I couldn't afford to be Union, cost several thousands of dollars to be Union. only Hundreds to be Confederate.) Confederate uniforms coul be regulation gray ot butterscotch, ora combination of the two. Leather accessories didn't have to match everyone else's in the group, and if you didn't have a cartridge box and/or cap pouch you were not given grief.
I never heard of a reenactor (aside from Buck Skinners) catching flack about their cutlery.
The 9cm Small D-D
