I have the chance to pickup a vintage Electro Harmonix 1970's clone theory pedal for $100.
This pedal is solid black on the front all the way past the knobs with a large red square and black lettering. All of the other vintage theory pedals I can find on the net have a smaller black square with silver lettering.

Any idea of the value? I would assume it would be the first production of these pedals in the 70's?