What about that weird gadget called the 'eBow' (i think?)
If you used distortion and held notes similar to a bagpipe you could get something pretty close.
p.s. there had to have been wah pedals 20 years ago.. mine's at least from the early 70's. (Mister Cry Baby)
I even remember reading about the eBow back when I started playing and that had to have been the early 70's.