Sorry, guys, I must have missed this one the first time around! As Feileod pointed out, I replaced the stock fenders on my M416 with wider custom ones. I wanted them to serve two purposes:
1. Accomodate the wider tires/axle.
2. Stand up to trail abuse better than the stock ones.
JK Customs in Hutto, TX built them for me about 5 years ago, and they've held up well. I've actually been thinking of having them make me another set that incorporates a mount for a propane tank and offers some protection to the fuel cans mounted on the sides of my trailer.