That is the Exact-A-Rip fence. I had one on my craftsman tablesaw for years. It was better than no fence, but not by much. Very frustrating to keep square.
I call BS! This is very similar to (and copied from) the Ridgid AC1036 fence I have used on my C-man saw for the last 8 1/2 years. It is similar to the ones Ridgid sold on their saws (like the 4512 mentioned above) and if you had trouble keeping it square, the problem was with the operator, not the fence!
There is a real problem with T-square fences in general - being supported only at the front end of the saw, they can be bent out of alignment by pressure against the fence as you feed pieces through the saw. This is why I like the Ridgid design - it clamps at both ends of the fence and you cannot move it when applying pressure against the fence as you feed stock through the saw. That includes the Mulecab and the homemade fence you refereneced.
By the same token, I used the original fence that came with my saw when sold (a 113.29901 sold in the late 60's) and had no problems with it. I still have that fence and, if you want it, I will be glad to send it to you. My biggest problem with it was the travel - it would only cut 12" to the right and 24" to the right which is why I moved to the AC1036. But square - yeah! straight - yeah! solid - yeah! Should bolt right up to your saw. PM me and we will talk.
As for the comments about "had a .030" bow in it", that is more a reflection on the ********************ty Chinese quality of extrusions used in these fences, not on the design! My fence has less than .001" from one end to the other across the 30" table length!
There are lots of opinions here on LJ - not all of them have much knowledge behind them.