I’m interested in buying this but can’t find reference to the odd-looking hour hand. Presumably a service hand?
Would it affect the value?Its on a BoR bracelet with Gay Freres signed clasp but unfortunately the pro seller can’t confirm that it’s all genuine.

 

Both hands look of a similar age to me, and not matching the watch. Yes it will affect the value a bit, and replacements would not be easy to source, especially ones with aging to match. I would start by asking for better pictures so you properly assess the dial condition too. It looks like it might be OK, but it looks a bit washed out in the light and there is detail missing. Hard to say for sure. Case is also polished which will affect the value.

 

Excellent, many thanks