Well we're getting there. The first disaster was what came from Ebay, Swann Morton yes but disposable meaning made of thin plastic. The blade was steel so I tried to use it in the advised way, ie two or three slices and snap, right? Wrong, the thickness of the spare plastic I was given I measured with a Vernier, 3.2 mm, about 130 thou I think, which is pretty thick, so I pressed harder on the blade and it snapped in half, the scalpel handle did. The blade flew across the room, luckily there was no-one else there so I retrieved the bits, wrapped them up in a tissue and carried on with my stanley blade. Eventually, I had cut it so much that it snapped as I wanted it to.

Then I filed the ends at 45 degrees and eventually it looked like I was there. I held the plastic on a square and glued it with MEK. Then I added a square bit of plastic (came from china today) to reinforce the angle. I know its not the greatest bit of work you will ever see but that plastic was thick. Still I achieved my goal. I will try to .upload the picture I took if I can - see how thick the plastic is. The maximum size I have ordered is 1mm, or forty thou from Plastikard, roll on that arriving. Any advice anyone has might help.