Now, if you really want that sound, you could always replace the lugs with JP2Creations repros, they are high dollar, but keep the overall integrity of the kit. They are milled from a solid piece of metal and look like the real thing. If this kit were to be kept all original, it would be better to keep tension off the plastic heads and tune it only as needed to play, but using calfskin all around is the ideal to keep the lugs from cracking, if they aren't already. Replacing those with originals is getting very expensive these days.
There are a few discussions on this forum about "repairs" to brass B/B lugs so that they can take the higher tuning requirements of plastic heads over calf, but if I were to own an original with the lugs intact, I would go calf all the way around. That's just me, though. Many others would do differently, and each to their own, but for my money, those brass lugs are calfskin era and should be played accordingly.