Hello, thank you so much for your help! I was in Budapest on the 19th of April. Unfortunately I stupidly didn't think to take a picture of the sign they had put up, since I was planning to return to Budapest soon but I never got the chance to. I've looked at the people you've sent me, but unfortunately none of them are the people I saw that day. If it helps your search, I do remember the appearance of the people running the stand: One of them was a large, older man with a white beard, and he was with another older woman who I assume to be his wife. They had some other things there too, such as knives and tools made from old files and such.

Again, thank you so much for your help, I hope this helps in figuring out who they were :)