Suunto compass bellows replacement

[MarkTheBike]

Hi all
Like so many of us, my binnacle compass bellows has failed and dumped all the oil into the bilge. I have done what I think many others have tried and made a new one out of a folding cup (+ Johnson's baby oil) and it seems to be holding but I'm not convinced it's an 'industrial' quality fix. Luckily I was able to take the old bellows out of the base cup and, although quite crumbly, have managed to glue it into a decent semblance of its original shape. Obviously it can't be used in this condition but has anyone tried using one to make a mold and creating a new one out of soft silicone. I've not done any silicone molding before but it looks possible. I think a Hardness value of 25A - 30A should be 'floppy' enough but would really appreciate any advice on manufacturers, techniques, etc. ...or, of course, that these soft silicones aren't suitable for immersion in oil!
Cheers
Mark