Does the seal cros section they gave you look like a T?
If so take a look at 10,000-12,000 series at this link.
If there are two grooves for seals, does the seal they gave you look like the one at this link?
I am betting on the first, very common and easy to get T seal sets at most industrial seal supply houses. I am thinking with the dims you gave it may be a #214 Greene Tweed T seal with zero or one back up. Internal grooves of small bores hard to measure unless you have the right kind of mics, don't know what you have.
You should be able to find an industrial seal supplier there in the DFW area and maybe even a Greene Tweed and Parker distributor if you think it may be one of their seals you need.