Lost all gears while driving., 72 tail shifter, cause confirmed in post#17. Input requested Options

[Mr.Nobody]

Well, I'm currently typing this as I await a tow truck on the side of the highway so please forgive the grammatical errors.

72 4 cyl with a factory tail shifter.

I was driving down the highway and had shifted into fifth and was continuing to accelerate to a cruising speed when the car held for about 3-5 seconds then popped out of fifth. I tried to put it back into fifth and it would not go in, it wasn't there. I could place the shifter, release the clutch, and the car would just rev. I dropped down to fourth and it was there and held in place. I continued along and then tried for fifth again, nothing. Went back to fourth and it was gone along with everything else. Coasted to the side of the highway and shutdown.

On the side of the road the clutch appears to be engaging and disengaging as it should. When I move the gear shift there is an noticeable difference in feel, therefore no resistance to movement and no noticeable notch into the gears.

Under the shifter looks good, the bolt before the firewall is still tight connecting the two front and rear sections of the rods.

From looking under the car (I have not gotten it jacked up yet) the firewall bushing appears to be intact and in place. The rods are connected immediately aft of the firewall. At the tail I can move the lever in, out, and fore and aft, but there does not feel like it's connecting and going into any gears.

I've searched a bit and read something about an internal roll pin in the tail of the transmission. Not sure if that's my problem. Need more research.

I'm now sitting in the tow truck headed home. Opinions and thoughts welcome and appreciated.

Thanks