NMC EXP,
What you have I believe is a post WWII “long slide” Lyman 48. Per my memory the post-WWII Lyman 48 came in two sizes. To quote from the Lyman catalog:
Series 48 Receiver Sight with standard elevation slide (up to 600 Yard)…$12.50
Series 48 Receiver Sight with special long slide (up to 1000 yards) ……….$14.50
The standard slide was calibrated to 60 minutes while the long slide was calibrated to 105 minutes. I still have a “long slide” on a M1903.
I do not know how much windage adjustment the new 48 has but it’s more than plenty.
I believe that the pre-WWII 48’s were calibrated TO 125 minutes