I use felt strips on the batter and on the reso. My batter head is an Aquarian Force 1, which is a single-ply head with an interior damping ring (similar, I think, to Remo's Powerstroke 3). Reso is an intact Aquarian Modern Vintage single ply. No bedding or other laundry within.
Although my vintage kit is from 1970 or so and all of its toms came with adjustable muffling knobs, I dislike the effect they have on stick feel so I do not use them. I do like some damping, so I fit all my toms with Remo Pinstripes (or equivalent) on the batters. I use Aquarian Classic Clears on the resos.
It's kind of odd that some people get picky about whether it's appropriate or not to use external damping (whether with felt, gel, or special heads) on vintage drums when so many of the vintage drums I've seen (and own) originally came with some sort of damping mechanism built in.
If I want a bit of damping, should I only use the knob-and-felt doughnut thingie that came with my drum instead of putting a Pinstripe or a piece of gel on it? And just suffer with the change in stick feel? I'd rather not.
I also use the original shell-mounted tom mounting system, although it is said that they dampen the drums' vibrations relative to modern suspension mounts. Modern drums sound so "boingy" to me.
Vintage, modern, muffled, open, every drummer's sound is his or her sound, however we get it.