Not really buying John's tuning method, here is why. Natural resonance and pitch is more complex than simply being based on the naked shell. As you add hardware, the overall mass and density of the drum obviously changes. This will change the fundamental pitch and resonance.
The fundamental might be a C# on the naked shell, but once you add hardware, the fundamental may go up or down (memory no longer serves). In any case it definitely will change.
I think you will have much better luck checking the fundamental with all hardware attached. Here is another major factor, mounting systems. Those old MIJs are capable of sounding terrific, but many of the mounting systems just plain sucked.
I've done experiments and was shocked at the results. I had some MIJ drums that sounded great off the mounts, I timed the resonance of the fundamental pitch which had to my ear a resonance of about 4 1/2 seconds before the fundamental was no longer discernable, but as soon as I mounted it using the early 70's mount that dropped to about 1 1/2 seconds. That's a HUGE difference. The drum that sounded beautiful and resonant suddenly sounded like a cardboard box.
I've tried the same thing with more modern mounting systems and found a much smaller drop in resonance, but a significant one nonetheless, from now on I will only use rim mounts. With them there is VERY little resonance degradation. And that all will be true regardless of the heads you choose.