Having received new supplies of resin (having first received new supplies of money courtesy of my employers) I've been able to try out casting some duckets for my new models of 11 and 12.
The results are very satisfactory.
The first couple of casts had to be scrapped as they came out of the mould too soft and became distorted. I think probably because the ambient temperature was too cold during the 'big chill' last week. (My study isn't heated as luxuriously as the rest of the house.)
Being the first use of new bottles of resin may also have something to do with it I suspect.
The second pair were left much longer in the mould - around an hour - and the cut outs in the side for the windows were supported and kept square while they cured fully over the next 24 hours.
Having been glued in place on the carriage sides a little extra beading detail was added to finish them off.
I think the parts are almost ready to be glued together into a carriage body shell now. How exciting!