If you are VERY familiar with your home city, you can also scout out
the garage sales in communities which were "new" in the 1970s
I see things like Mattel Intellivison's, original Apple II systems and
such but they always seem to appear in areas which were newly built
in the early 1970s. My wife and I attend garage sales all through
our city, but only certain neighbourhoods seem to have the classic
computers.
Still looking for a working Exidy Sorcerer...
Thomas