I decided I was as happy as I would ever get with the size and shape of the brass base layer for the curved end of 150 so I have progressed to fixing the styrene layers on top.
What you see here is two layers of 10 thou styrene which is thin enough not to have excessive urge to spring back flat and will hold the shape of the brass when it is bonded to it with superglue.
That's equal to the 20 thou base layer of the main body side parts and the next step was to add the beading using 15 thou strip.
I made the curved corners the same way as for the main sides by filing a crescent into a piece of styrene and cutting it out very carefully and fixing it into each corner.
I think now it's ready to be used as a master to make a resin copy which will be the 'production version'.