USA on blade Question

[Pat60]

Hi I live in El Cajon where the Buck knife company was. I got 4 folding buck knife from a yard sale All have the word buck filed off the blades but it has made in the USA across the blade is this real ? I have them on e-bay as a lot of 4 I Can not find another with made in the USA on the blade and I have 4 if they are not real I want to remove them.Thanks for any help.not sure how to post a picture