Does anyone know where I can purchase New aluminum diamond tread triple axle fenders? I have been searching the web and haven't come up with much.

A local mom and pop trailer manufacture to me (Tampa Bay) makes them. I have bought a couple trailers from them and they are great to deal with. I dunno where you are if they would ship but they are Owens and Sons (Aluminum Slide-On Trailers).

http://www.championtrailers.com/
http://www.mcclaintrailers.com/

If you need some I have them in stock and they aren't a lot of money

How much for a set of this style

I am at home now and don't have prices with me but a ball park for aluminum tread plate should be under a $100 each. i can check tomorrow if you are interested or just give me a call at the shop
631 848 2246 - Neil

I am also interested on a price in that style.

I don't recommend the style that have the decorative drop in between each tire. I had them on my last trailer.
1) On hard turns the tires can actually contact the drop portion and damage the sides of the tread. (I had to open mine up larger due to damaging tires.)

2) They are usually installed when the trailer is unloaded. When you load the trailer with the boat, torsion axles rock back anywhere from 1/2 - 1 full inch. Then the decorative drop sections make everything look off center. (Opening them up a bit alleviated the off center look, but I knew it was there.)

I my opinion without them the trailer looks like a hunk of **** cheap trailer