Can't shift into 4th and 5th gear Options

[dcheek]

As my topic title states I can't get 4th and 5th gear.

A little background:
I have a bone stock 1976 914 with 26000 miles. I'm the original owner.
I had this trouble a couple of months ago and found that the conical screw on the shift rod coupling by the firewall had worked out. While I was at it I discovered the nylon bushing and cup in the shift console by the trans were toast. I replaced them and put everything back together and all was good. Also, the bushing on the firewall was fine. Then I started to have issues grinding reverser going from 1st to 2nd. Then it got to the point that I couldn't get 4 th or 5th. So I put the car back on the lift and checked all the above mentioned items I replaced. They all were tight and intact.

So, I'm thinking it has something to do with the gearshift lever up front?? Maybe the coupling up front is not tight? It does feel like the shifter lever has more slop than before.

I'm pretty sure the trans is okay since it has very low mileage.

Is checking the shift lever up front the most logical place to start the diagnosis of the problem?

Dave