Marc -I have found the relay locations vary depending on year of production. In the service manual 1968 group 07-14/11 the most forward relay is start enrichment relay for the injection pump, the second relay from the front is the cold start valve solenoids but gets its signal power from the front relay (terminal 87 to 86) with ground signal sent from thermo-time temp switch 35c, the third relay is 2nd stage of the start enrichment injection pump with ground from thermo-time temp switch 5 celcius. What I do to determine which relay I am working with is to apply battery voltage to pin 87 and listen for what clicks.
Also, somewhere under the 6.3 forum is a tutorial for these relays.