hi ya Jay
Sadly, my personal Leeds Castle has now long gone.
Anyway, props - they were 5 bladers and I am sure they were something like 55 or 60 mm diameter (I think - 80 % certain).
The original motors were 600 but they were too thirsty on the old amps because I was planning on doing a 24 hour scale sail with this model originally. So, I bought 2 (I think they were Johnson motors) 12 volt - they were low drain - they were very similar to those that you get in an electric drill (size wise) but, as I say, the amps were something like 1 amp on 12 volt free running. I remember I had the old MFA Olympics belt drive gear boxes in. I remember I had to open up the mounting screw holes in the plastic gear boxes - also, I had to take a little bit plastic off the bottom of the frame of the gearbox - because the motors were just a little too big to sit correctly in the gear box mountings. I ran it on 12 volts. As luck would have it, my computer is screaming at me saying it needs new disc space for more downloads, so I have just ditched a load of pics including Leeds Castle photos - to try and make more space.
Here is one picture of the replacement for my old Leeds Castle - which I am busy building at the moment