I bought a 1966 (the 626 "special" zig-zag) T&S at a thrift store a few days ago for $12, and it does NOT have plastic gears. I took it all apart and cleaned it...it sews beautifully. And the in-place bobbin winder is AWESOME! I don't know why my $1K+ Bernina doesn't have that! :) I plan on taking it up to our cabin to have a machine there, and may even teach my 7 year old to sew on it.
IMO, it'd be a great first machine for someone.