I've had success, at the second time of asking, with the latest moulds.
As I predicted a few days ago the silicone did set super-fast this time.
Rather than still being soggy after four days, this time it turned solid overnight.
Clearly I have now gone to the other extreme with too much catalyst in there, but at least I've been able to reclaim the masters and start using the moulds and here's what's come out of them...
What you see here are the bits for the ballast hopper doors, the Z struts for each end and the brake cylinders and vacuum reservoirs which are cast in halves to be joined together.
The next step is to fix these bits onto the prototype wagon to check they fit properly and look right before I set about preparing some more moulds for the production run.
For these I will be grouping some of the parts together in the same moulding box to speed up the process when I come to run off the kits.