Local bitcoins would be your best way to buy directly from a seller paying whit cash and whit out traces.
LBC requires KYC and so is a very poor choice.
If you are ultimately pursuing the goal of making your bitcoin savings legitimate, then you will have to sacrifice something, (after all, you need anonymity so that you are not pursued by the law at the moment, right?)
There are a thousand reasons to want anonymity that having nothing to do with evading the law.
In addition, you yourself know that there are trusted persons on the forum who earn money by acting as intermediaries, and after a year or more no one will remember your name because thousands of parcels pass through the hands of such people.
There is no way you can think you are private or anonymous simply because x amount of time has passed since you compromised your privacy. You have no idea what kind of records the person you are buying from keeps, how good their security is, who else might have access to the details you send them, if they have been intercepted, how they are stored, who else might have looked inside your package, the list is endless.