The good news here is that because I've chosen to fit gears to drive all the axles, I don't need to worry too much about getting the coupling rods and crankpin relationship spot-on.
coupling rod etch
That small piece was loose when I first opened the box. I've been worried about losing it ever since so it'll be good to get this done.
Soldered, filed, the holes opened with a broach then finished with wet-and-dry.
The pins are a good tight fit, but I may need to make the holes larger to get things running when I fit the cranks on the wheels.
** May 2007 **
When I examined my prototype more closely I realised there was some more work to be done. The overlays around the crankpins are circular, and very thin. I tried to represent this by filing the overlays thinner and rounding the edges as much as I could.
the lower rod here has been trimmed