Screw for Scope Mount

[CPC]

Not sure if I should have posted this in the wanted area but thought an optics expert might help me determine what it is first.. redfiel, weaver, etc. Purchased a rifle with an old Weaver scope and this is the type of mount screw that was used. It is missing one of the screws and would like to replace it before buying for new screws, since I believe this may be an early period mount screw... any help or advice would be appreciated.. first trying to identify it and then trying to replace it..
regards,
CC