Your town had me stumped for a minute, I suspect it's supposed to be Oxford not Oxfold. I still had to look up Oxford tho.
I don't know of any FL State Parks which would offer what you want. O'Leno right now doesn't have many campers but it has a few.
Have you thought of the little known Florida State Forests? They offer camping and I think you can camp, boondock really, in the Goethe SF section between Newberry and Bronson on State 337. Here's the website:
Goethe SFYou'd have to check with them about the permit but they are near you.
Other than that what about boondocking in Ocala National Forest?