WATCH REPAIR TUTORIALS & INFORMATION

Can’t see much just the screw in the hole on side of movement , 

Did it already run fast when it came into your possession ? What work if any have you done on this ? It may have had the hs swapped and be incorrectly timed to the balance wheel. The balance wheel may be too light for the hs strength. So either of them changed and not set up correctly. But more likely after all other simple visual checks ruled out such as hs contamination,  this is an old watch and it may have had the hs break at the stud which is easily done on an old weak spring, while carrying out  a service and lifting out the balance assembly.After repinning, the spring is now too short to be within correct regulation  It may be possible to add weight with timing washers to the balance wheel if there are timing screws or lesser a task maybe enough to bring the timing screws out to decrease the balance wheel's speed. You would need to poise the balance at the same time, bit of a faff though. Now shorter the hs may act more aggressively making timing more difficult on a t/g . Post a photo to help with this. 

As long as the mainspring isn't set you can clean it and reuse it. This site has the measurements for the mainspring.    

Thanks John, that will surely be helpful when I get time to continue the reassembly, My watch is different in that it uses a thumb slider for start/stop instead of the crown.

I get that and you are right choosing a scope is not easy, I'm on with that at the moment and i wont go until i know i have it right. There is some very misleading info and video out there, my first big mistake came from just that. I would just hate to see any harm done when Alex made a simple boo boo. Anyway enough said lets us let this error disappear .