I also have a Leaf razor handle with some single edge blades. The $5 pack of 100 Derby blades also fit my unbranded straight razor I got for like $15 20 years ago. They both work really well for specific things so long as that specific thing isn't getting through airport security.

My grandfather was a barber and he gave me one of his 1960s era Gillette Safety razors. It's a pretty cool mechanism on how you load and adjust the razor.