Early Marine Scoped Rifle

[cplnorton]

1903's used what is called O&E blocks, correct?

that one pictured has an odd screw pattern, not at all like the (admittedly very few) originals I have seen

Yes, John Unertl copied the Unertl O & E off the WWI WRA Springfield Marine bases.

The blocks are nearly identical except for slight differences in the machining at the ends of the block.

They are nothing like the blocks on the Senich Rifle.