That's a good point, John. I was looking at the 33" and it didn't occur to me that that was actually the size of the prototypical wheel on the wagon. Which reminded me of something else, on another thread I seem to recall that there are different lengths for the axles, that is to say the width of the axle from tip to tip where it fits into the wagon. I think limas were a little shorter or longer than Hornby or Bachman. I'm going to search for that other thread too.
EDIT: John & David had some input on the other thread here:
http://irishrailwaymodeller.com/showthread.php/3484-Old-Dapol-amp-Lima-CIE-Wagons-on-Peco-Code-75-track?p=54291&highlight=lima+axle#post54291
If rewheeling, it is worth remembering that Lima vehicles use a shorter, approx 24.5mm axle, as opposed to the normal approx 25.75mm axle that everyone else uses, although I believe some smaller manufacturers offer their wheels with different length axles. I personally just reuse the original Lima axles with new wheels, although it can sometimes be a challenge to remove the Lima wheels from the axles.