No one is now making 58-59 front fender bottoms. (that I know of)
The problem is they would fit only 2 years so the cost to tool up vs sales would not be worth it. We looked at making that part. (We make low demand parts with power hammers, hammer forming over dies, bucks and the like)But it would wind up being a expensive part and we did not think we would sell many.
How bad are yours? Perhaps you will beable to find some good fenders. I have seen some for sale but they tend to be very expensive.