I have obtained a used fretless Fender Jazz (MIJ) a few months ago. This is my first fretless purchase. When I bought it the action was pretty high & I didn't think much of it. After I bought it I took it home and I lowered the action to get some more mwah out of it. I now get some pretty noticable buzz at some fingering locations. I am assuming this is because of fingerboard wear from the previously installed roundwounds. (Let the buyer beware!) I have tried to find a balance of an acceptable higher action and keeping some mwah, but haven't found it yet. Any ideas on what can be done before going to the expense of dressing the fingerboard? And, if that is the only option, what would it cost? Any thoughts on the would be greatly appreciated.