Hinge... that was a custom job -- a relative of my ex who has his own shop made a few for us. We had to be careful as XPLORX4 said re: heat... it was a matter of making a few welds then letting it cool...
Latch... mine is pretty much the same as above... I was going to go snap a pic, thanks for saving me Dean!
Tires... I've had the Revo AT's since April 2005 and have had no problems, they didn't seem to alter my millage much, they're good in the winter, and I love them offroad... They may not be mudders, but they have seen a lot of mud, and rocks, and they haven't held me back.