This is a workalike of the Ampeg Scrambler. This board will accept a variety of different transistor pinouts for all 4 transistors, and one pad will go unused for each transistor.
If you get the transistors from Steve at Small Bear (which I highly recommend), please note that the pinout of the 2N5306 he sells is ECB, not EBC.
The most recent revision merely adds a missing capacitor to the schematic, and corrects a notation for one transistor. The layout is unchanged.