Hey. The spring feels just like it did before I lost reverse. The knob itself, the reverse lockout mechanism and spring, and all six forward gears feel exactly as they did before I started monkeying around with this new shift knob. It's just like reverse gear simply vanished. The shifter won't even go slightly into reverse.
I retraced my steps and one error was that the "Lift-up Reverse Lockout Shift Knob Adapter" I used wasn't large enough to fit over the lockout mechanism (the "shaft"). It was the exact same size as the lockout mechanism. M12 x 1.25". I had hand-screwed it on a few turns before I noticed this and thought "crap, I need to order a different adapter" so for my amusement I lightly screwed on the new knob (Mishimoto MMSK-BK) and it felt awesome. Anyway, I screwed off the new knob and screwed the adapter off and then screwed the stock knob back on by hand until it was good and tight. Suddenly, I couldn't shift it into reverse.
I guess I was just hoping that I made some common mistake that could be relatively easily fixed. I've looked all over the web and see a lot of "my Fiesta makes grating noises in reverse" but nothing at all about feeling like there's absolutely no reverse at all.
If anyone out there can help or needs more info, please let me know. And thanks.