Speaking of guessing, the board pictures pretty much suggest the HB could be "Dyna Green Distortion"--a variation of the Dyna Red Distortion. Check the DRD schem here:
https://www.freestompboxes.org/viewtopic.php?f=7&t=5502
The circumstantial evidence:
1) The same author
2) The statement about disinterest in the circuit after starting to trace it
3) Two green LEDs v/s two red LEDs
4) Two back to back 1N4007 diodes in both
5) A lonely 1N4007 and a lonely Zener-like diode in both
6) A single 8 pin IC in both
7) A single FET or TRANSISTOR or TO-92 device in both
8 ) The same number and function of the controls in both
9) Approximately the same complexity in terms of the number of resistors and capacitors. In particular, the HB has 5 electros while the DRD has 6; nonetheless one of the electros in the DRD is 0.47uF, so it could be perfectly implemented with a non electro cap in the HB.
10) There is a statement in the third post of the thread linked above suggesting the DRD is a variation on the HB. At that time there was not much tangible evidence, but these latest pictures certainly support that.