I know I'm the least knowledgeable one in this discussion, but I'm scratching my head over the photo Major 2 attached to his first post in this topic. The plaque labels it as a Walker, but the darn thing sure looks like a Dragoon. I never saw a Walker with a loading lever latch on the front of the loading lever.......looks just like my 3rd model Dragoon.
That is the conversions with added lever catches ( probability done at the time of the conversion) to solve the annoying drop lever syndrome.
.... If you look at the C&B guns in the Lobby card photo ( these were the close up guns ) the lever is as you'd expect.
Paramount and Western Costume both were capable to mold and produce Rubber Guns of all styles )
I've had many Rubber Enfields , complete with rubber bayonets , A Rubber flint double barrel SXS ,
If you watch close in films you see the bayonets wiggle ( Glory & Gettysburg )
sometime bent at odd angles... In Alamo Travis used the SXS & Crockett use a Rubber Filint Long Rifle to swing at Attacking Mexicans.
In close hand to hand the Stunt men swat each other with the Rubber props ,
Reenactors however enjoyed popping the hell out one another with the Rubber guns.
Can't say Eastwood carried any ( perhaps in fall horse scene ) But I'm not surprised some were in the prop trailer.