orange kmd overdrive, c4570ha opamp??????

[czech-one-2]

just picked up one of these old kaman/kmd overdrives.sounds kinda like a very transparant sd-1 with the added bonus of alot more bass content due to the bass potentiometer.
it uses dual symetrical diodes [red with blue stripes] and dual inline opamps [c4570ha]anybody familiar with these opamps? or can you identify these red w/blue stripe diodes?
this pedal has replaced my ts9 and sd-1 for my low gain overdrive.it seems to sound more natural and there always seems to be a little clean [unprocesed] signal in the sound.
anybody have a schematic or more info on this cirquit?
happy thanksgiving, bk

[czech-one-2]

oh,that may be a green stripe on those diodes.
bk