Blimey, sorry the delay, I've been meaning to get back to you.
I'll take some pictures as soon as I can, and give you some dimensions.
Also, I remember after we found it I googled for info on the thing and got directed to a link on ebay. A guy had had one for years and couldn't get any replacement springs for it so finally out of desperation got an engineer to make one for him, turned out he had to have 50 or so made to make it economic, anyways he was selling the others via ebay to re-coup his costs, might be worth you while having a look out for them.
I'll try my best to get the pictures and dimensions posted here by the weekend.
LL OH.