That is correct. There is not enough room under the binnacle of the smaller boats of that age for the Lewmar drive. I investigated it for my 2001 37 and even on that there was no room for the frame and the drive.
While below decks drives are inherently superior, the wheel drive is operating well within its capabilities on a 31. The loads on the drive are much lower than on the larger and heavier boats so the weakness of the drive mechanism is not such a problem.