Hi Dan, sounds like it's condensation forming on the inside of the crystal. Not sure if you're planning on having it serviced but if the gaskets are replaced that should help prevent it happening in future.
Thanks,
Steve

: Hi collectors
: I recently acquired a very original 2446C that has an odd
: behaviour. The crystal is hazy when it’s at room temperature
: and completely clear when it is a little warmer. I have never
: seen this happen before and would love some advice.

: So far I have polished it with polywatch and then been a little
: more extreme by taking it back a little with fine sandpaper, but
: the weird problem remains. Anyone have any advice or seen this
: before?

: Cheers

: Dan