I have a 2011 VISA ERB and needed a new fender after I had a tire blow out. It was a nightmare trying to get a new fender. Dealers don't like dealing with Gulfstream for parts. I finally found a real person to email at Gulfstream who finally gave me a part number and then a dealer who would finally agree to order it. I couldn't buy it directly from Gulfstream.
However, since 2011, the trailer was redesigned to ride a little higher. (Mine is way to low and constantly bottoms out going up small ramps especially at gas stations.) When they did the changes, they changed the fender skirt to a totally different shape and they would not guarantee that it would fit. I ordered it anyway since you can't see both sides of the trailer. I took the old one off and installed the new one in less than an hour. The screw holes pretty much lined up as well.