Apart from cleaning them up I wasn't planning on preparing the edges, they havent in Joe's design, the V is running on the natural small radius of the edge of the steel angle, the V bearings can be run inside an angle which seems a better way but I could'nt think of a simple way to mount an angle in a suitable attitude.

Angle I've shown is 25mm x 3mm I would rather use 4mm or 5mm 20mm angle but that isnt a size that we stock at work.