I am concerned about the amount of tyrosine that you are giving your father.

Its Tolerable Upper Limit is in the range of 0.4-6 g/day. You are giving him, being conservative, about 3.5x that limit and are thinking about giving him even more. Giving him so much tyrosine could well have adverse health consequences.

I strongly suggest that you consult an evidence-based health professional (ideally somebody whose knowledge includes PD) before continuing to medicate your father.