Years ago I posted a small family of fonts on DaFont. It had minimal character set and was not quite polished. I didn't include a EULA with it, and I tagged it 100% Free. (Not the wisest thing to do.) In the meantime I completed the character set, redesigned some glyphs substantially, and altered the family structure. Now a potential client contacted me wanting to purchase an exclusive license, or preferentially, a copyright transfer. (I know the latter would not be in my favor, is more complicated legally, and so on.) Am I running into any trouble by agreeing to sell the new, completed and refined, version of the font? Am I able to do that?
On a sidenote, to what extent is DaFont's '100% Free' label legally binding without a EULA? The FAQ says to always check the EULA, and since I failed to provide one, does it mean people have the right to use it commercially?