I really like the horse mounting story. Can't speak to validity, but makes some sense.
I figured it was due to the gun scabbard and lasso laying on right side, but don'w know for sure. Riding since I was born and never asked!
As for left side of tractor- yes. After all, it has several horses under the hood (35 in my case) and it would seem unnatural?
Seriously, though, I agree with the FEL hydraulics and 3pt hydraulics and all the hoses and stuff. Most machinery I run, including the larger stuff, is that way.
HINT: Don't park your tractor in low range/reverse. That puts the shifters in the way. Use M-H and Fwd on the semi-shuttle lever. Caught my shorts on them more than once /forums/images/graemlins/blush.gif
-DiskDoctr