G'day Locksley,
Nice job you are doing, and with those figures, I used a modified set on my Sirius Cove many years ago.
Like you, there was nothing suitable in the set for a helmsman, so I did some serious abdominal surgery on a couple of the bodies and came up with some standing figures. As I'm in the model manufacturing business and working in Urethane, I'm able to cast what I want.
The one major advantage of the urethane is that you can simply cut off an arm, re-position it and glue it back on with superglue.
These figures are cast armless and the arms can be shaped, to a point, to suit most applications.
The figures are in 4 bits, lower body and legs, upper body and head ( two head positions ) and the two arms. I could probably help you out with a couple, but the postage would probably be more than they are worth. PM me if you want more info.
I also needed a couple of crew for a larger scale pusher tug I recently built and these needed to be 100mm high or thereabouts, so I bought a set of 4 Chinese Kung Foo figures for about AU$10.00 posted. Most poses were totally useless for what we need, but again, surgery and silicone and new figures were created. The interesting thing with these Chinese figures was that the softish plastic that they are made of does not glue or allow filler to stick to it. I did manage to get a mould made before it all came apart!
Damien now has his pushy which he rides to work on, and stows on the after deck while on shift!