Wow, how did I miss this thread? The machine that I've had the longest and still have is my Viking, top of the line, purchased in 1970, after my first year of teaching. I was able to get a teacher's discount or I wouldn't have been able to afford it. It still works just fine and I let my SIL use it to learn how to sew a few things..... she's sewing machine phobic.
I also have access to my grandmother's treadle (it's at my sister's house at the moment). That's the machine I learned on back in the early 1950's. That poor machine has seen better days, put aside when Mom realized that her 4 daughters needed a newer machine to do all the things we wanted to do. But I rescued it from a neighbor that let her kids climb all over it and I did get it back to sewing okay. I had to send it to my sister's house when we were moving and haven't gone over to get it back to my place. I need to do that.