or will it? I'm really asking those with experience: Does practice REALLY overrule left- oder right-handed natural disposition?
I say this as a drum teacher of many years: YES! YES! YES! Practice and experience will eclipse any natural handedness, at some point in your musical journey. For my adult left handed student, six months of casual practice was all it took. If, from the very beginning, he were jamming with a band somewhat regularly, and had been practicing sticking and rudimental things -- daily -- on a pad from the beginning, it would not have taken even that long. But, as adults, we have other responsibilities and obligations that get in the way.
For left-handed students that are young beginners, it's less of an issue. We do, of course, spend time on developing the right hand. Some exercises are as simple as 16ths (RLRL), with the bass drum playing quarter notes. There is, of course, some awkwardness to fight, but please realize that we right handed drummers fight to build our left hands up. You could look at leading with the right hand, as a way of developing your weak hand, instead of as a waste of time. It's doubtful that your hands are matched in skill, at the present moment, being 35 years out of lessons and all.
I hope I'm not beating an already long dead and buried horse here. For me it's an essential question. It may well be that in a few years' time I will never look back on this thread. But at the moment I have a decision to make: mirrored Michy Dolenz setup or go with the percentage?
A few years time? I would think it's not nearly that long. My prescription for shortening the journey would be as follows:
1. Good/proven practice methods from in-person (or virtual) individual instruction. Your
practice methods are the single best predictor of success, not "talent" or handedness.
2. Daily practice pad work with a metronome. I use and teach from Bill Bachman's materials, and would recommend his online video series (Extreme Hands Makeover) to get your hand technique together.
3. A band, or some ensemble playing, once per week, because there are just some things that can't be learned in isolation. Record the rehearsals. In your case, you will put valuable "mileage" onto your leading hand.