I'll join the "me too" movement. I've long been a fan of the Gemmer conversions. I'm also a big rolling block fan. I've toyed with the idea of having one made. But never pursued it.
I like the the look of a shorter barreled Gemmer style saddle rifle. Here is an idea that has been rattling around in my head. I have this
original heavy .44-77 Remington #1 sporting rifle barrel. It has a damaged chamber and been cut to 23.25". I thought of having it relined to .50-70. Of course I could just have it rebored to .50-70, but that would require the barrel to be shortened further, and rethreaded due to the longer .44-77 chamber. Then fit it to a military #1 action. Add a rib, thimbles and wiping rod, maybe a finger extension off the back of the triggerguard. Not sure how I would make the stocks, I'm not a woodworker, so would probably have to farm that out.
Here is the barrel, and my original #1 sporting rifle before the barrel was removed and replaced with a new 32" Green Mountain .44-77 barrel. That short, heavy barrel is quite imposing. I think it would look quite at home as a Gemmer conversion