Hurrah! Lucifer the Loom lives again When I got the loom I was given two lead weights, which I assumed were those used by weavers to add tension to any loose warp threads.
Looking online last night I decided that my loom was similar to, but not actually a genuine Lervad loom so widened my search for info to all Scandinavian Looms. Eventually I found one which used lead weights on the upper lam (the bit which pulls frames down as you lift others) instead of strings to the treadle.
Obviously there were once four weights for the loom, so experimenting with strips of lead flashing and insulating tape I soon had Lucifer treadling nicely.
The saying is true – good things come to he who weights