Vintage 1970s '70s MXR Envelope Filter Block Logo Block Backplate

Here is one of the holy grails of vintage envelope filters, also known as auto wah effects. This 1970s '70s MXR Envelope Filters is as good as advertised, with warm, round-sounding, vowel-shaped, analog-colored sweeps for funk, rock and, of course, those Jerry Garcia and Grateful Dead tones. This one is so pristine that all of the interior foam is intact, a rarity for these pedals. Therefore I can't even get to the POTs to date the actual year of manufacture. However, there is no question this is from the first era of introduction from the late '70s or perhaps very early '80s, pre-LED light. Here's the thing: I already have a vintage Mu-Tron III and a reissue Mu-Tron Micro-Tron III. So, as much as I love this MXR, my envelope filter cup runneth over. Therefore, someone else should get to enjoy this amazing analog pedal from a bygone era.