I'm back on track with this one now. I've decided to use a Mashima 10/20 motor coupled to a High Level Slimliner Compact+ gearbox, my previous 48DS's used 10/15 motors. The change of motor was due to a conversation with Chris Gibbons (High Level) whilst ordering the motor and 'box who advised me to use the bigger motor if possible, at the time I was going to stick with a 10/15 + flywheel (I ordered a 10/15, this is now in the spares box). Whilst building up the gearbox I got out my spare 10/20 and, with a bit of fiddling, decided that it was possible to use the bigger motor and fit a flywheel. What makes this possible is the fact that the gearbox is articulated around the idler shaft making it possible to shift the motor back. Here's a pic, the new chassis on the left and one of my originals on the right;

I wish I'd thought of that earlier!

Pick-ups, brakes and weight to be added.

I'm rather pleased that I have fitted the bigger motor, remember that this loco is for someone else. I'm quite happy to accept a loco that is possibly slightly underpowered but I wouldn't expect anyone else to be!