There is lots of room for knees and heavier set people up front in both positions on a T-16. Plus steering is with tiller bars so you don't have a vertical wheel in your chest taking up space as on other types of carriers.
Nuts and bolts are all modern fine or coarse thread so even grade 8 replacements are easy to source and affordable. And most of the engine, tranny and brake parts are readily available, having been used for 20+ years on common commercial Ford vehicles.
Some of the reasons I went that route instead of getting a more traditional British/Canadian Mk I or Mk II pattern. Link below is the MLU thread where I have a series of photos of my vehicle being restored so you can see the space available if you browse through them.
http://www.mapleleafup.org/forums/showthread.php?t=9136