Need these bolts

[Jolby]

I know that these are 3/8-24x1 1/4, but I am having trouble finding them with a flange head or in body bolt fashion with the washer. I hope that someone can help since the two that hold the back bottom of the fender are broken and rusted in. I am doing fender repair and I prefer to install fine thread nuts to stay consistent with the rest of the truck. These bolts are used to hold on the hinges, fender bottoms and top rear of the fender up top. I would like to have replacements and spares. Thanks for any assistance.