The way you state your question, gives me the opportunity to give a obvious answer. What does "fully mastered" mean for you. I agree with Stevebob, this is an impressive list for four months of playing. I play piano for let's say eight years, half an hour a day, and "The Entertainer" is one of the pieces I like to play, but I still don't "master" it, and I'm almost never (but that's maybe due to my character) satisfied, I'm kind of sure that I would never say that I" master" a piece. So, if there's one piece of advice that I would give to you right now is stretch you're repertoire, and try to listen carefully to what you're doing. Try to play these pieces with spirit, maybe record what you're doing and listen carefully. I'm sure you're quite good but I do think that you're very good, but please be prudent. The piano can be unforgiven, and the satisfactory joy you're having now can quickly change in violent disappointment. I should say, stick on with you're technique and you're enthousiasm, but dig way deeper into what you're doing, for example 'fingering'... Good luck and kind greetings.