Hi Stryker,
Thanks for your kind comments! It was very satisfying to get it working.
Yes I had to experiment with the wiring on the workbench to understand how to do it. Once I worked it out, it was a quick job to solder it up.
Connections going straight to the Bodner are basically two wires - one is the common 5v which goes to one side of all the switches which arean't on the 12v circuit (i.e. not illuminated). The other side of the switch just needs a wire direct to one of the terminals on the Bodner that signifies a button. These switches can be from anything - no voltage or amperage restrictions, just metal to metal contact is enough to make it work.
The lighted switches are all automotive parts so require 12v supply, which is from an old laptop PSU. The relays are therefore rated 12v too (cheap auto ones). One side of the 12v supply goes to one
power terminal of the relay, the other side goes to the switch and back (when switch thrown) to the other
power terminal of the relay. So, flicking the switch on energises the relay and also lights the switch. The common 5v of the Bodner goes to one relay
switch terminal and the other terminal of the relay
switch goes to the Bodner board button terminal, so that when the relay is energised the Bodner connection is made as well but not on the 12v side of the relay.
I think this is the exact panel
http://www.ebay.co.uk/itm/Racing-Car-12V-Ignition-Switch-Panel-Engine-Start-Push-Button-LED-Toggle-3018-/140955370965?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20d19845d5Yes the switch with LED is like the one you linked, but it is included in the panel above so you don't need to buy both (it's under the red cover on the left).
Sorry I don't have any wiring diagrams but I can take photos and draw a few sketches if you get stuck
Regards,
m