I was fortunate to get some of the Hump Yard Purveyor manual actuator levers and that's what I use for my train order signals. They use 'choke cables' but these are finer ones that were designed for model aircraft controls.
Hump Yard Trail Order by Edmund, on Flickr
Hump Yard is one of those MR suppliers that simply disappeared so I imagine you'll only find them on eBay or HO swap.
You could use the Tortoise 'remote actuator' which comes with teflon cable and bell cranks then adapt some kind of manual lever rather than using a Tortoise machine.
Good Luck, Ed
Looking for hand control for a two arm train order board. Looked at thottle/choke cables, seem like over kill too heavy/long. If I could get a handel/knob to fix on the tortoise cable and some way to secure the cable sheath to the front of the layout that would work. Thank you for your time.