I am seeking your advice because I have heard that you are very knowledgeable.
My arms will not grow any more. They measure 14 ½" at 5'10".
I do five sets of curls and five sets of triceps parallel bar dips because these are the best exercises I know.
My reps average 12-15 each set.
Your arms need more work on the muscle fibre. Till now you are building more capillaries than muscle fibre.
Try 2 exercises for biceps and 2 for triceps. 6 sets of 6 reps each. No rest at all between sets of biceps or triceps.
Rest 10 minutes after working biceps before going to triceps.
Perform routine three days a week. Do not baby yourself. Work over your head. Make each rep tough. Go all out. Do not save yourself for future sets. Each will take care of itself.