Ruger No1 quarter rib screw?

[kayaker1]

Hi all,
I recently acquired a No1 S and it is missing a quarter rib screw due to a previous aftermarket sight installation. Does anyone know what the thread/pitch is for these so that I can find one locally?

Thanks!

 

[Stevebot-7]

Maybe get in touch with Western Gun Parts. They're in Edmonton and if they don't have one they might at least be able to give you some information.

 

[remp49]

The screws are #8-36tpi.