Well, my first attempt at this build was a complete disaster, but it did at least teach me (the hard way) some important lessons - most importantly to always thoroughly test the motors, radio and running gear, and make sure everything's working correctly, before getting started on the modelling/detailing work. Also, that RTR "fast electric" hardware is not suitable for scale boats!
After building the Glencoe 1/72 WW1 Subchaser (the predecessor of the WW2 type) and buying a copy of the Squadron/Signal booklet "US 110' Subchasers in Action" I was inspired to get the incomplete SC out of the loft where it had been gathering dust, and make another attempt at completing it, this time with a bit more experience with R/C installation and hull construction!
Firstly, most importantly, I got rid of the toy RTR electronics (keeping the motors and running gear, which are usable) and installed a proper radio with ESC and rudder servo. I used the same 9.6v ni-cad battery as before (and made a new battery holder out of styrene card), running at scale speed with an ESC you get a lot more running time out of it, and I also have a couple of spares of this battery type.
Secondly, I sawed off about 2cm of the curved stern and made a new transom stern from styrene sheet (sealed + reinforced with epoxy) The hull is now reasonably accurate in shape for a WW2 SC above the waterline - the stern below the waterline is still completely wrong, but you don't see this when the boat's in the water!
I've got plenty of reference material - both drawings and photos - including the above mentioned "In Action" book and photos of the very impressive Fine Art Models 1/32 model
here, so references for detailing shouldn't be a problem. I'm planning to scratchbuild as much as possible - including the guns - but the scale is close enough to 1/48 (actually 1/45, not 1/43 as I originally calculated - probably partly due to the sawn-off stern!) that I can use commercial fittings, and crew figures, in this scale.
Here's the interior of the refitted model. I had to cut a large hole in the aft deck to provide access to the motor + steering gear - unlike the radio + battery areas, there are no convenient superstructure parts over this area so I made a removable, overlapping deck plate held in place with small "rare earth" magnets.
It uses a removable RX/ESC unit (I use this setup in most of my non-sail boats now), the 27mhz RX shown has now been replaced with a 2.4ghz one.
The motors, couplings and prop shafts/stern tubes are the same as before, though the props are now 3-bladed scale types. The single rudder (the real SCs had two, but I didn't think it was worth bothering with a scale rudder setup given that the hull below the waterline isn't accurate in shape anyway) is a commercial brass one cut down in size a bit. The steep angle of the prop shafts is not optimal, but was how I originally installed them (in an abortive attempt to get more manouverability from the twin-prop steering system) and the shafts and motor mounts are so solidly installed that I didn't really want to remove them (as it turned out, the model runs and steers fine, anyway)
The last 2 photos above also show the new stern and keel.