Well, folks. I'm no expert, but I have tried to read up on the subject.
I do not know the twist rate of the original mausers in 10,75x68, but today most barrels are delivered with a 1:14 twist, equal to that of the .404 Jeffery.
Original caliber diameter was as 9,3x57 sais .424", but again, today most new barrels are delivered with a .423 diameter, same as .404 Jeffery.
So basically most of the barrels sold today are the same for 10,75x68 and 10,75x73 (.404 Jeffery)
When it comes to bullets, this gives us the opurtunity to use the same as the Jeffery. Also it is possible to take .429 pistol bullets and run them tru a rezising die. And fortunately for me, there are two guys here in Norway making bullets for this caliber. One makes affordable lead cast bullets, and the other one swages hunting bullets from solid brass/copper. He can also custimise bullets for each intended use

Also there are bullets from Woodleigh, North fork (if they are still in business), Barnes (I think) and Hornady, and possibly some others as well