Parashooter,
The 35Win is so far off on volume and no current data was the reason I disregarded it. The closeness of data for the 308 starting loads and 30/40 max loads made it seem like a better choice for "extrapolating" data. 2-4% less expected pressure  in the Krag sounds good also.
The pressure curve you posted is in PSI not CUP. Would 51K PSI correspond with Hodgdon's  42.8K CUP?
If so, using 45 grains as a max safe load and looking for an accurate load in the 41 to 44 grain range will be the plan.

Rich, Losing body parts does not sound like fun, if I use Lyman's 47 grains as a proof load it will be with the gun wrapped in a towel, tied to an old tire and the trigger pulled with a string.