Quote Originally Posted by Dimman View Post
Could also be a 'New' (for the time) FHF 98:

https://perrinwatchparts.com/collect...28929703215138

Same bridge pattern, but thinner (3.6mm) and higher beat rate (21600).

Edit: Have you found this in your search?

https://www.watchrepairtalk.com/topi...n-walkthrough/

Edit 2: Also this:

I would have thought 96 as that what I thought I saw under the hair spring looked like 96 then in a cloud with either fhf or eta ?

or


be interesting to see a close up of the hair spring