For the 2 LEDs that are used in this circuit. Does it matter or make any difference if they are 3mm or 5mm?
Also, the square markings for the LEDs on the PCB are NEGATIVE, right?
The stock unit used 5mm, IIRC. Either should be okay.
In this case, the square marking is negative on the board, although that is reverse of what it should be. I need to update that image to make the square marking positive!