Screw size for vintage G&L SC-1 bridge saddle

I am missing a screw for one of my bridge saddles. I am not talking about the hex height screws; I mean the screw that determines intonation, the one with a spring. Does anyone know what size screw that might be?appropriate?

The size is 4-40 x 5/8”.
Reference post: viewtopic.php?p=101057#p101057.

The size is 4-40 x 5/8”.
Reference post: viewtopic.php?p=101057#p101057.

Thanks very much