I noticed in the latest Huntington's catalog that they show that Bertram is making 10.75x68 brass. Anyone have any experience with it?

My experience with Bertram brass in 10.75 has been very bad. It is soft, the rims are thin and you had better look at the primer flash hole before priming to make sure it's there. Virgin brass loads fine, but on the second reload, I have to use a Lee crimping die to hold the bullet in place. I have Horneber and RWS brass also and reload it with no difficulty. Huntington used to carry Horneber brass in 10.75. I use the Bertram to load swedged down .44 Mag pistol bullets which is about all it's good for.

Call Huntington's to see if they have it in stock.
I ordered some fairly "off the beaten track" cases recently. They had them in stock.

You can always get some from Reimar Johannsen in Germany. I think it is on page 110 of the English version of the online catalog.

I think you'll find a consensus that Bertram is at best functional and in general, pretty poor. At least that was my experience the only time I tried some.