The most common SPDT relay, at least in the car audio industry is just a little black cube that is about 1" x 1" x 1" sometimes with a little bracket attached or molded into it for a single screw, and on the bottom, there are five male spade type terminals on it... below is a picture of the bottom which shows the numbers as in the diagrams above...
I hope that sheds some light on what the numbers are and helps you put it together... This next picture is the same picture but someone has added a diagram of what is going on inside...
Anyway, I ordered my Cheese Box and should have it soon... WAY before my truck is even running! lol Damn I need to get that thing back on the road so I can resume carputer install...
TTYL!
Coach... aka Randy!