Did you ever get this fixed? I saw a diagram of a '93 that made it look like the only two relay positions were in the right-most column one up and two up from the bottom. Fuses have two contacts but relays always (?) have to use 3 or more contacts.
Do you mean the panel will have two relays once you get this one plugged back in, or it already has 2 relays and this is a third relay you are certain goes into that relay box?
I have an '88 Olds 88 that is probably the same as yours... if you're still around to view the topic let me know and I'll check it. I can't remember for sure but I thought there were markings on the panel itself or on a sticker, did you use a strong flashlight to see if you can find markings? If I don't have any I can at least note the fuse and breaker positions.
The other way of attacking this is figure out what electrically doesn't work or use the cheater method of plugging and replugging till you can't find anything that doesn't work. Plugging a relay into a relay socket that never gets energized because you don't have that equipment in the car is not a problem, just be sure you aren't forcing a round peg into a square hole so to speak, that you can see it fits right where you put it before the power is back on.