Trapdoor Rifles

Hello,
Just a new find can anyone recognize any of these soldiers?
Sorry the quality is not as good as the unresized scan

Here is a little bigger? size

No one I recognize, but apparently all officers except the guy in the center of the middle row, but he may be a chaplain who were sometimes not uniformed. Three in front and on just left of top center all have colonel's,eagles. Scowling fuzzy face on the center left seems to have a star.

There is a wide variety of different (and perhaps non-regulation) uniforms (shoulder straps, different style epaulettes, different collars, different button arrangements, some with/without the [1901?0 waffle aigulettes).

I am pretty sure this is not a grouping of Regular Army officers, but perhaps volunteer/militia types, perhaps at marksmanship competition somewhere, or maybe some sort of big convention, or possibly a veterans reunion. Dark whiskers at top center has several ribbons or awards not seen on the others,one of which is similar to the Grand Army of the Republic badge which is similar to the Medal of Honor pre-WW1.

Taken in a studio, not outdoors.

Thanks John
I was not sure if Regular or Militia, some of the buckles look like regular but it is hard to tell

I could be mistaken but the gun in the top row on the right may be Napoleon with a mustache??
https://en.wikipedia.org/wiki/File:Jacq ... roject.jpg

Dark whiskers at top center has several ribbons or awards not seen on the others,one of which is similar to the Grand Army of the Republic badge which is similar to the Medal of Honor pre-WW1

Here is a close up of the medal, GAR, and ribbon which looks civil war unit?

The back row right end guy looks to have an 1860 cavalry saber rather than an officer's sword.

The spaghetti and waffle cords on the chests of 3 of the men are "helmet cords" which were attached to the M1881 pith helmets theoretically to prevent loss, with one end attached tot he helmet, the other to the chest of the uniform. Looked fancy, but not sure it actually worked very well.