The outer NBR seals have an aftermarket replacement from Corteco. See my pictures.
The inner Viton / flour carbon seals don't have a replacement and the OEM ones are NLA from MB. The outer diameter should be OD=57,15 mm wich is non standard. However OD=58,15mm is a standard dimension with the same ID and width as OEM.
I bought Viton radial seals and removed 0,50 mm of material on the outer perimeter in a lathe. There was enough material to take from. The rest of the dimensions were exactly like OEM. I made some extra ones (two complete sets), but they are sold to G friends now.
You can do this carefully with the seal ring mounted on a large socket using a cordless drill and a piece of emerald paper aswell.
The seals in my box were very stiff. I think they age well during 30 years because of the high temperatures that the TC reaches under 4x4 load (>110-120 dgr. C).