Running too fast

Beautiful condition Omega 300FHZ fully working but unfortunately it is running too fast so requires an adjustment/service. The watch is in a fantastic condition throughout, gold plated case with a stainless steel screwdown caseback.  

Looks to be in a original condition, signed crown, quick set date function which is also still working as these can be a bit fragile on the electronic movements. 

Genuine interest highly appreciated as this is a nice watch, dial unmarked, case has the very minimum marks to it and comes on a brown strap.