(how old is old enough to qualify as "vintage".
I have wondered that myself. I guess it depends on how old we are ourselves.
I would love to have a treadle too. My mom had one, but it was never in working order. The treadle part needed welded or something I guess, but the wood is beautiful. My sister has it and it has a place of honor in her home. She has no desire to ever have it fixed, but just likes it. I have told my sisters that I want mom's old Singer she bought when I was little. I remember her buying it brand new in the late 50's or early 60's. My dad still has it and still uses it for mending. Not sure what model it is.
I love the fact that some of us are saving these old machines from junkyards and restoring them to their original beauty and purpose.