It would be great if there were some pictures of these.
Ryan, why do you dislike a stirrup?
I spent 4 hours looking for a stirrup one time that fell on the floor, only to have the lock break a month later when one of the tiny pins in the whole infernal affair sheared off.
I have no doubt that the mechanism can be splendidly reliable and smooth, but as Dan pointed out, I sometimes get highly suspicious of our dependence on using castings for parts that were originally forged. I know, this is probably an unwarranted prejudice bordering on superstition, but there it is.
My hat is off to the wizardry of the Harmans and Mantons of the world.
I've been mooning over the Ketland on the Mansker rifle as I'm building that gun now - standard frizzen spring (no roller) and I expect a standard mainspring as well. I have been wondering if I could "detune" a Chambers Late Ket and make it with no roller.