Is there any early videos of him speaking where he exhibits stuttering (or other speech impediment)? It sounds like when people who "self-treat" (intentionally

Is there any early videos of him speaking where he exhibits stuttering (or other speech impediment)? It sounds like when people who "self-treat" (intentionally or not) and substitute one impediment for another, ideally one less apparent. Then again maybe it's one of those habitual things, for example when someone says "Knowwhatimean" repeatedly.