> Anyone recommend a replacement for this jfet opamp?
MC34002 sure looks like a slight variation on TL072. IIRC, the '072 will have a little more GBW, a little less slew, a little better noise, none of that enough to say "WOW!" or even "wow" about.
If you have a dead MC34002, drop in a TL072. $2 at Radio Shack and available in every civilized country.