Well, the closest thing I can find like that was a mod I’ve made (see the second half of the 1st post My first mods! An experience, for sure!).
It had only a mechanical side switch, with in-built charger, but not mini-USB! The tail was flat and had a huge spring on the inside; I drilled and filed and added a mechanical reverse switch and a rubber tailcap.
I would question: do the mechanical side switches have mini-USB entry? I’ve only seen them with other kind of entries for adapters.
Also, I think the best way to get a flashlight similar to what you’ve asked about is to get a tailcap with a mechanical side switch (like the ones of Solarforce of the C8) and trying to make it fit the light with the side switch.
Opting for this, I just don’t know if the charger will work properly…
Not sure of this helps, but here you have it 