Yesterday came home to a leak at meter box, flooded and couldn’t tell if my side or municipal side leak.  City came and shut down their side and determined it was my side.  Friend and I dug up my shutoff which City inadvertently buried when they put in smart meters months ago.

 Break was a popped pvc joint so we replaced pvc fitting and reinstalled my shutoff which is an older Barrett globe valve.  Turn on water only to find that this Barrett valve had some sort of check screw in the side of the bonnet that is missing and was plugged with debris. With the valve open it weeps through this hole now and I can’t determine what size screw plugs it but it’s threaded.  Anyone ever see a valve like this and know what type of plug screw works?

I don’t want to go with a ball valve because I’m afraid the increased water pressure would dick up my old house plumbing and taking the old valve out would be tough now because there’s rock below that prohibits the stem from turning. Id likely have to cut the valve.

It's old. Just take it out and put in a 1/4 turn ball valve. (Hint: you don't have to open it all the way.) PVC is easy. Cut it, glue it, done. And, it's all cheap.

Just make sure valve is for potable water (NO Lead.) I prefer metal valves. Stainless is nice.

Starting to think the hole was for a water pressure gauge, so maybe a 1/8” or 1/4” npt plug will work.
The valve itself functions fine.

Is the "hole" a drain built into the shutoff valve?

I know this is obvious to everyone but unless you’ve got water running constantly, you’ve got exactly the same water pressure in your house whether your shutoff valve is open, half closed, or straight-piped.