Looking for 7.92x57 B Patrone or PZ 7.62x54r

Good afternoon everyone, I’m looking for some pretty mythical cartridges in the Milsurp category. I work with a friend who have a fairly large YouTube and as a gift for a his new mosin, I’m trying to track down some of the aforementioned rounds to record. I could also use 7.92 Mauser as I do have a 98k.

My apologies for typing this in the general chat, however I saw Ian from Inrange has success doing the same, even if no one on here has any, perhaps I could be pointed in the direction of a reputable person who might.

Appreciate any possible help.-Mat