PGA Stone Hopper - PRMRP Kit

I wanted to have a mini block train of these, but the kit is seriously frustrating to build (I've done two now). The sides are supposed to have horizontal kick out where sloped sides meet the vertical but the bend is impossibly small, and folding the ends to match the sides, it's one piece from the buffer beam to the top of the wagon, with no guides leads to disintegration. Trying to hold it all to solder is... difficult. I've prepared it for Yeoman transfers, but a full set is in the order of £50 - so it's staying grey.