Saw is working. Needs finishing off, proper vice, switch, arm rest and a coat of paint.
I must say it is very slow, so will start by adding weight to the arm.
I drilled the holes to mount the blade 2mm longer than the blade pitch in an effort to avoid a complicated and time consuming blade tensioner, but the blade wobbled on its first cut. I then added the 16mm threaded rod. nut and piece of pipe to push the two arms appart and add the desired tension.