The TC and TCS are both type 74, and yes, there are TCS cars with 4-speed boxes.
...and as Brian said above, for various reasons, swapping an original 5 spd for a 4 spd is highly plausible.
I have a Special with a 5 spd. I bought the car three years ago and when I was shopping, the 5 spd was a 'must have' for me. Honestly though, I very rarely use 5th gear. I've put 10,000 miles on my Europa since I bought it, and have engaged 5th gear less than a dozen times. It really boils down to the type of driving you do, but (in my opinion) on the type of roads on which the Europa is most at home, there is no use for a fifth gear. Interstate type driving is boring, and occasionally uncomfortable in the Europa. If I was shopping for a Special again, I wouldn't pass up an otherwise great car because it had a 4 spd. In fact, due to differing ratios, a 4 spd may actually be preferable, though I haven't examined this perspective this yet.
Keep us posted on your search/buy. Cheers.