Ham,
I have reloaded for both 7 M/M08 and 7x57, the standard 7x57 is quite a bit better than the 7 M/M08 with handloads.
My top standard 7x57 high velocity loads in a 98 Mauser with a Douglas barrel 26 inches long.
154 grain Hornady, 2923 Feet per second. Winchester 785 powder, compressed load
145 grain Speer, 2939 Feet per second. Winchester 785 powder, compressed load.
145 grain Speer, 3037 Feet per second. Norma 204 powder.
The above loads worked up 1/2 grain of powder at a time to each load to reach top velocity without any pressure signs.
Most accurate powders, H380 and H4895 at .406, .448 and .419 inch groups.
W785 no longer available shoots under 3/4 inch.
Your fireforming loads seem mild for a 7x57 Ackley Improved. I usually use close to full power loads when forming improved brass for the Ackley improved rounds like the .257 Roberts Ackley Imp and the 30-06 Ackley Imp. Haven't worked with a 7x57 AI though and it depends on how the improved chamber was cut headspace wise.