That is a fascinating piece, especially considering how few of these early Pallweber watches have survived. Since you are considering restoration, I would be careful about doing anything cosmetic before the watch has been properly examined.
I’d start by documenting everything as it is now with clear photos of the dial, movement, case, and any markings or serial numbers. Then have a specialist familiar with early IWC watches assess the movement and case separately. For a watch this old, preserving original parts and finishes is usually more important than making it look new. I’d also ask the restorer to identify any replaced or non-original components before agreeing to work, so you have a record of what is original to the watch.
If you can share a clear photo of the movement and the case/serial markings, those details might help narrow down the production period and identify exactly which Pallweber variant you have.