My local photo store can not get an Ilford footswitch new or used.
I just missed out on a footswich on Ebay.
If anyone wants to part with this part I am interested in buying it from you.
Otherwise I need to figure out the "pinout" on the four prong foot switch connector plug to the Ilford 500 Multigrade head and a source for the connector.
I decided that trial and error might damage the head so if anyone can help I would be very grateful.
The attached scan from the service manual shows the required connection - you connect the switch between pin 2 and any of pins 1, 3 or 4. From memory, the plug you need is a standard 4-pin DIN, which you should be able to get from any electronics hobbyist store.
If you use Ilford Multigrade 500 system with control unit or Analyser 500 from RHDesigns you need "momentary on". Control unit switches the enlarger off automatically.