[sdiy] Vanilla electronics question

[rburnett at richieburnett.co.uk]

Are there any features on the PCB to identify which supply wires are 
meant to be positive "+" (RED) and negative "-" (BLACK) ?

Are there any features on the PCB to indicate which way around the LEDs 
are meant to be fitted ?

Actually, can we just see a photograph of both sides of the PCB please 
!?!?

Possibly the two LEDs were fitted the wrong way around, so someone 
decided to swap the RED and BLACK supply wires over, rather than 
desolder/rotate/resolder the LEDs.  To me the Schottky diode is there 
purely for reverse polarity protection, nothing more fancy.  The 150R 
resistor seems appropriate to set the current through each LED to around 
30mA with a 12V supply.  With a 6V supply the LEDs will be dimmer.

-Richie,