I built this for my friend Chris Stelloh, the Yuma Wray in Miss Shevaughn and Yuma Wray. Excellent Americana duo, go check them out!
The multiplex is wired for tails (only the delay line is bypassed) and has an oscillation/infinite repeats switch instead of the tape detune switch. The gain and EQ contour of the preamp is adjustable inside, as is the oscillation switch's behavior. Tons of fun. A full build report with notes on all the mods is in the 1776 Effects corner of the Madbean forum.
I did a more thorough demo of the Multiplex itself -- this video is more to show off the unique characteristics of this build and how all the parts work together.