I have the PBM paddle steamer sitting on a shelf, badly needing some restoration work. It was a bit tender as it came so I ended up adding an extra 1/2 inch balsa bottom with an external ballast keel moulded from lead shot and polyester resin. It also needed an enlarged rudder to improve the steering but with these mods it handled well. The geared drive was very noisy so I replaced that with a friction drive with silicon tube on the motor shaft running on an aluminium disc, much quieter with no gear noise. Probably still got the original Bob's Board wired in.(Also have their oil rig supply boat.)
Jim