Good call, I did actually email them prior to posting in our forum here. My hope was that someone may know the exact replacement seal.

In the meantime, Brian at Borgeson responded the very next day. At first he said to ignore the issue because this is just a dust seal...I responded by suggesting that he may be thinking of the bigger one that sits between the housing and the pitman arm once it's installed, whereas in my case it's actually the seal that's pressed into the case.

He asked for some photos, said if this is an oil pressure seal we would have to ship the box back so they could repair it.

I've attched a couple of photos of what that seal looks like in my steering box. I'll send this over to Brian to see what he makes of it.