Well, after fighting with the front seal on the transmission for a few days, I finally got it out. I tried using chemicals to melt the rubber portion of the seal. I tried using a slide hammer to yank it out. I tried using a long rod and large hammer to push it out from the other side. In the end, I scraped away as much rubber material as I could and simply hacksawed a slit in one edge to loosen it up.
Here's the hacksaw after cutting the slot. The seal pulled out with a pair of pliers after this.
The cause of much frustration over the past few days.
The mostly clean hole left with the seal removed.
Here is the new seal in place. Even after lubricating the seal and the surrounding hole with oil, I still had to use the throwout tube and a large hammer just to get it in. It took almost as much force to put in as it was to take out. I didn't even get it flush.
Here's the throwout tube installed.
With the front seal back in place, I added the rear gaskets, wetted them with transmission oil and installed the intermediate plate with gear shafts. This actually went fairly smoothly.
Here's the rear transmission cap installed. It was a bit of a trick to get the reverse gear to slide into place since it sat inside the rear cap.
Here's the shift support installed with a new O-ring and gasket. I also have a new shift rod bushing and cap over the protruding ball.
And finally: The throwout bearing installed.
At this point the transmission is fully assembled and just needs a load of oil. Yay!
Next up, filling the transmission with oil and starting on the potbox installation. Installing the electric motor and the potbox requires some rare hardware (rivnuts and hex-head nuts) that I hope ElectroAuto will send to me.