I finally got round to building up my original thin PCB PiPod. The Instructions didn't mention what battery to buy and unfortunately the one I purchased - 103450 - was too thick to use the original bottom.

This is a 2.75mm deeper base which allows the thicker battery to be used.

I used FreeCAD to add the extra depth. Some of the apertures are elongated but don't look too bad. The original buttons can be used though.

Its a fun project many thanks to the original designer.