Manual for RICO VAS

I am looking for a manual or a copy of a manual or
a contact to get a manual for this variometer. Failing
that can anyone tell me the set up procedures for Netto
zeroing (the vario zero is easy to figure out) and
setting the wet and dry speed to fly pots? This is
the model with pneumatic probe Total Energy, climb,
netto and wet and dry speed to fly.

The RICO I have been using has somehow lost its settings
and I have made it worse by tinkering. Any help or
pointers would be gratefully received.

John Galloway