Welcome to the forum!
What are you wanting to do with the Garden Tractor? I use mine for everyday work, I don't like the older smaller models of garden tractors, they aren't very practical for what I need. I have a Simplicity 7016 with mower and rototiller. That model of simplicity was made between '75 and '79. I also use a Bolens HT23 which was made between '79 and '87. I do not dislike the old machines, but normally they are less user friendly.
My first garden tractor was a Sears Custom 7, it was a early 60's model, I ended up putting a 16hp brigs on it and the old thing would pull anything.
These garden tractors are fun to play with, but I want to warn you, you can NEVER just buy one, before you know it your whole garage will be full