Weaver N2 Hole Layout

[Grendl]

Hey gang, just saw a worn Remington 511 at the LGS that had been drilled and tapped. Looks like four holes for a Weaver N2. Does anybody have an N2 one handy who can tell me how far apart the four holes are? Can't find it on the interwebs and don't want to make the purchase if I'm not able to easily find what fits the damage done.

Thanks!