Clad, Silver Rings & 1700s !!

First off hello to everybody. This has been my first real hunt since January. Over the winter I was looking for something to do as I couldnt detect so I figured I would do a little thrifting. Well, One thing led to another and next thing you know Im taking in an extra $2k-$3k a month thrifting so that has consumed all my detecting time and im not complaing at all. Anyways, fast forward to today. Me and my bright idea of deciding that today would be the day I get back at it in 105 heat index. I decided to hit a school a distance from my home but it has always produced for me. I headed to the back area of the school and started to hit the sidelines of the soccer fields. I manage to pull $9.05 in clad, two matchbox cars and also two silver rings. After a few hours in the blazing heat I couldnt take it but wanted to still give it a go. This school is in a historic area and 2 years ago I got a nice Morgan dollar just off the school property where there was a long stone wall and further into the woods I could just barley make out an old stone foundation. Today I thought let me head back into those woods where there was at least some shade to take the temps down into the 90s. I was moving along and about maybe 100 yards from where I found the Morgan 2 years ago in the opposite direction I got just a faint whisper tone. I circled and the tone stayed the same so I decide to dig it. I dug down several inches and nothing on the pinpointer. I dug some more prob like 6 inches now and put the pinpointer in and get a beep now. I dug down another like 3" and I hit whatever it was. I actually hit it twice. I continue to dig around and next thing you know I pop out a 1782 coin !! Now, I do not go in search of old relics but each year I seem to stumble upon something historic.

So, Im gonna post some pics and maybe you history buffs can tell me exactly what this is. Date is def 1782, it is very thin now but you can see that it had a reeded edge. On the front around the outside it says "CAROLUS III DEI GRATIA" ...on the back it says "ET IND REX 2R F F HISPAN"....Im no history person myself but this is pretty cool to find....Somebody please get back to me and let me know if you have some info...It would be greatly appreciated...Cheers !!