For really deteriorated lenses, I've had good results with the Black Baron kit:

http://classic-motoring.stores.yahoo...apllepoki.html

 

You can take the lenses off and reseal them with silicon.

 

Obviously the first you need to do is determine if it's moisture on the inside or something (contamination, oxidation, pitting) on the outside. Since the razor(?) treatment worked at least temporarily, it sounds like it's on the outside.

 

looks nice