Anyone know the screw size and hole spacing (centers) on the tang of a Marlin Model 1897 lever-gun? I want to mount a tang sight and need to order a base. I get 1.14" with a vernier, but would prefer to 'know' what the actual distance is. Thanks.

The hole spacing is 1.125", or 1 1/8". I believe the screws are 8-40.