The information I've researched has the pressure measured in Europe back then during the development of the Mauser SR actions and the cartridges, including in Germany, as using the "bar" unit of measure. The figures were reported for the 7x57 in the development of the cartridge were for a MAP of 3900 "bar". That converts (1 bar = 14.5 psi) to 56,550 psi......? The 7.65 Argentine had the same bar MAP. The 6.5 Swede was 3800 bar (55,100 psi).
And as I told you earlier EVPAT using a conformal transducer at the case mouth which give slightly less pressure than when measured a mid case body. Perhaps that accounts for the slightly lessor "peizo" measurement on your data sheets.
Have you looked at the SAAMI and C.I.P. MAPs both CUP and transducer to actually see what the difference is?