MARK, i made the actual moulds for the Clyde class lifeboat some years ago and they are accurate for one of the 3 boats only…….70-002 Grace Paterson Ritchie. the other two boats 70-001 Charles H Barrett and 70 – 003 City of Bristol were both slightly different to GPR and to each other………..but the hull cabin, flying bridge, fore companion way were grp mouldings.
However, i gave them to metcalf mouldings, who passed them on to Models by Design, who eventually sold them to Mountfleet Models.
i did make a full set of rubber moulds for moulding resin fittings and for personal reasons sold all of those moulds for fittings to Adrian Gosling at Speedline models for 2 pints of diet coke..
i would suggest you contact Adrian and ask him if he still has those fittings moulds and if so, run a set off for you.
hope this helps you.but beware.they need an incedible amount of ballast, and very large motors to power them,