Most people on this site will tell you to avoid aftermarket body panels as much as possible. That's what I have done and even though they all need media blasting and painting, I would much rather go that route than take a chance on thinner metal that won't fit.
In my case, I was able to find NOS or good OEM fenders from the Parts Forum on this site. There is a junkyard in California I can get you the number to and there is a guy in western TN that has a vast supply of nice OEM fenders. I'll get you their numbers when I get home.
Here is one junkyard guy I do have the number to. He is a very impressive fellow to work with and will ship fenders properly, which means wooden crates. NEVER allow a body panel to be shipped to you unless it is in a crate. Many though you will have to buy in person.
I have bought 5 NOS or OEM fenders from three members of this site in person and each guy was honest and reliable and the parts were exactly as they promised.
Eric's Auto in Billings, MT
406 325 2427
Ha! I found the guy's listing in TN. I've been there, he really does have all these parts. However, do get a pic of the fenders in question before going, he has had some theft from his junkyard in the past.
https://huntsville.craigslist.org/pt...332172487.html
EDIT: stepside fenders come up for sale on the Parts Forum from time-to-time. I'll get those numbers just as soon as I get in the door.