Early Fuel Evaporator Relay and Plug

Hello, I read a thread on here from a while back where a guy needed this part identified. It was a little silver box that mounted to the driver side valve cover. A plug with 4 wires inserted into this part. Another gentleman on here identified it as the Early Fuel Evaporator Relay. Essentially its job was apparently to send the signal from the pumps (auxiliary tank) to the single fuel gauge cluster the fuel level for whichever tank is selected.
My fuel system has been working great ever since I had everything but the tanks replaced in it. But the plug on that relay was old brittle plastic and upon doing some other work under the hood (kickdown cable replacement) the plug completely crumbled apart. This caused the wires to short to each other and blow the 20a fuze for the ACC slot, and I'm fairly certain the relay might be bad too. I opened it up and found some charcoal looking gunk connecting the solder on the contacts. (I'll upload pictures of it tomorrow). Either way, no dealership, no junkyard in my area, not even ACDelco or classic industries can find this part other than in GMs part catalog it shows that it's been discontinued, and thus, no part number or "superceded by" info. The relay circuit board has all the white insulation coating, so I can't read the numbers on the resistors and components inside. So I also don't know what the proper readings should be between A B C & D on a multimeter. If I could get a replacement relay and a plug for said relay, I can definitely rewire the plug and then it'll work, but I don't know which relay can successfully replace the OE relay.
If anyone knows where I can get an old one with its plug, or if they know which relay can replace it, it's be greatly appreciated. I've always got my phone on me so I'll be quick to reply.
TIA, Dan.

Here's a link to my trucks info. Maybe from the diagram some can come up with a part number. I know mine was printed on it, but when I cleaned the engine it washed away. I know old GM motor homes are a great source for parts. I found a guy on CL that had parted one out and was selling the 454. I was able to get some emissions brackets that the buyer would have just tossed.

https://www.autozone.com/repairguid.../Throttle-Return-Control/_/P-0900c1528004c499

That's a great diagram. Yeah piece number 3 is exactly what I'm looking for, as well as the plug for it. Or a replacement for both. Numbers printed on here look like
MADE IN CANADA
477322
Z-2940
EIGHT CYL
4659
The patent number on the receptacle is 3764976

So I found a replacement relay on eBay for a whopping $155. Still no luck on a new plug. I might just stick the wires in it and fill the whole thing with RTV

Here's a link to the vehicles that have that switch. C, K, P & G are the series of truck and 1, 2 & 3 is 10, 20 or 30.

http://www.gmpartswiki.com/getpage?pageid=99488

This company says they have 1. Doesn't give a price.

http://www.phillipsmusclecarparts.com/search-nos-by-gm-part-number.html

Here's another ebay seller here in Northern CA I've used. They part out a lot of GM trucks. If they have the part and it's not listed, they will create an auction for you.

https://www.ebay.com/usr/rayandsamantha

Thanks for the help, the fuel reading issue was just the fuse. But yeah it'll crank, but won't start so long as this relay is disconnected. I'm gonna hook the old one back up ghetto style and see if I can get it to start. If it works I'm thinking ill keep it how it is, and RTV the leads inside. And then promptly selling haha. I'm getting all this fixed so that I can throw it on Craigslist this weekend.

Just confirmed the relay is still good, so I'm gonna get a new fuse and RTV and then do a road test (never got to finish the first one after putting in a new kickdown cable.) Thanks for the tech data! If you know anyone in Kansas who wants a pretty damn clean K20, it's for sale

Hi is there any way to bypass that little box I'm switch from 2 tanks to 1 and would like to remove it of possible