Thanks for your answer !

Mine has the same PCB and the same transistors and white box caps as yours and it dates from 1976 according to the pot code (137 76 07).

Here are the pics:

Usually Little Big Muffs share their PCB with Big Muffs and this Little Big Muff transistor version is contemporary to the Big Muff Ram’s head and V3 version.

Is there anyone who knows if the EH-SPI board has been used in some Big Muff Pi version or if it is specific to the Little Big Muffs?