fender u nuts best place to buy?

My Napa here in CT has them in red and clear bags hanging from a turn style right near the universal window cranks and hardware. They also have a catalog you can look up by dimensions- not by make and model. You need to be a detective some times and stop relying on internet. In other words Napa can get them if they don’t have them in stock.
Aveco is also another hardware supplier to the shops with the countless draws full of supplies sold to smaller shops. They have an on line catalog and will sell direct to the public. Worth is another you see in the tv car shows a lot with the orange red like displays.

More ways to skin this cat for ya.
Good luck.
Amazon is also another way- eBay as well. Measurements and sizes for those bags of 50 or 100 is your friend. Sometimes the bag of 50 with the bolts are cheaper than 10 at Napa I’ve found.
It’s nice because they are used through the car in other places.
Syleng1