Hi Bob and Ray

I just found the name of the company who suplied the diode and receiver. Its
called

Laser Monitoring Systems Ltd
United Kingdom

I dont have an address for them, I tried to look on the web, but not with
much luck - I think the are situated somewhere in mid-england so it should
be possible to find an address somewhere. Also they seems to be owned by
another uk company called Neutronics Ltd - maybe someone her knows more ?

regards

Peter Neubert