Yes, keep them. If you don't find a buyer, hang them from your house on July 4

These might be military, and much older. There's no way to guess from one picture and I'm not an expert -nor is anyone else here. You might want to ask this in a different category -for some reason it's in fashion and accessories when History or military might be better. You will need to find a qualified expert appraiser -someone who collects flags, knows their history and knows their value. just asking randomly on YA. like this isn't going to get you anything but a bunch of wild guesses. No, I don't know anyone -but using google to search for vintage and antique flag appraisals might get you closer to a real value. In our situtation we inherited a statue. To find out if it was worth anything my hubby asked a few people he worked with -they gave a couple hundred dollars and a few said nothing. I searched for a professional appraiser and after she carefully examined the piece we found a maker's mark that indicated it was worth ten times that. Which we wouldn't have known if we hadn't consulted a professional.

That looks like a nautical signal flag. It has no special value.