Sorry to be a bit slow contributing to this thread, Madcat, but we have the converted iron boat referred to by Pete Harrison, Glenfield. The PD2 fitted in the '70s is still in it and has propelled us round the system over the last 2 years without a hitch. It's a bit smoky on start up and if revved hard after idling in a lock but otherwise has a clean exhaust and adequate 'grunt' for our needs. It is still mated to a 3:1 Parsons gearbox. Sump drainage is via a pipe fitted to the drain plug orifice.
I have some pics of it but Photobucket won't work just now.
Regards
SteveE