Aren't they standard 1/4" threaded bolts? I'm sure you could just take your camera/binos to a hardware store and try a few out until you find one that fits.
Iceman is right, the standard thread for tripod/camera is 1/4" UNC, 20 Teeth per Inch and should be easily available from hardware and automotive shops.
Geoff, if you still have your Orion, why not use the bold that comes with the mounting rings for piggybacking the camera to that. Oh and yes the bolts are readily available at any hardware store.