Does anyone know where to get these parts replaced?

[72 longhorn BB]

Hey there,
I am just putting brakes back together and I noticed a few things worn out.



The boot (A) on the brake rod, and the boot (B) on the rod that goes into the booster (C).

where can I get these parts for replacement?

Are they part of the vaccum booster (C), or the support bracket (D), or can they be bought separately?

Any help would be greatly appreciated.

I need to git-er-done, and this is holding me up.