Awesome find, I found a 2reale that I got at the beach two years ago, 1795 and very thin, It's posted in beach and shallow water, I posted it yesterday. Happy hunting.
I was very exited when I found it laying on top of the dirt . Got washed out of the bank where I thought was a hunted out spot. Found three 8 reales in this location all around the same date 40. - 50s. Minted in Mexico City.
Southern digger, in the top right corner of the original post is a red bar that says "nominate banner" click it and it will turn blue and direct you to a screen that lets you post why you think it should make banner.
I agree with the other posters - you just don't see the 4 reales very often, although Aquachigger dug a few of them in his big river coin spill last year. Yours is a real beauty. I'm curious what type of site you were at and what state? Finding three 8 reales and a 4 reale at the same place is very unusual unless you are on a shipwreck or there was disturbed cache or coin spill.
The only 4 reales I've ever dug was an 8 reales cut in half - see my avatar