At least around Michigan, the vast majority of sohc4's that you find (which is quite a few!) generally have at least one of these modifications. Thankfully, if you can get the stock parts, it is easy enough to put these back to stock, as nothing has really been "chopped".
Think how many rusty and title-less frames are gonna meet the axe when folks finally realize that the brat frame hoop and open triangle was a bad idea.