Yes, My carbs act up too !

Further to trying to discover the source and type of Crap in my filter I removed the fuel from the tank. Had run it down to "Reserve" on the last ride. Filtered what was draining as it came out of the tank. Pictures are a bit better now that I've kind of figured out how to hold the camera to the microscope. These are 40X magnification.
As with the Crap I found in the filter, it's both Organic and Mineral. Strands of something, crystals, some pieces that look metallic and who knows what else. Relative to the size of the filter, the tank had surprisingly little debris that could be collected from the fuel drained.
I'll stand by my original theory that this Crap is from year(s)? of using Service-Station paper towels to catch the dribbles. The only other source would be from the Fuel itself.
I'll let the "Conspiracy Theorists" run with this one. If anyone has another possible explanation I'd certainly be open to those ideas!
I'm hanging-up my C.S.I. hat, for now.
Simply keep an inline filter in place (and if you "re & re" it make sure you replace it correctly oriented!)

The final 3, that wouldn't fit in the previous.

Thanks for your diagnosis and description. It doesn't take much to bugger these carbs. I am going to need to strip mine down soon. I've developed a bit of stumble transitioning from quarter throttle to the main jets around 3000 rpm.

I hate the airbox. It gives me shudders. The rest I don't mind.

Ledkz1300 wrote: "I've developed a bit of stumble transitioning from quarter throttle to the main jets around 3000 rpm."

Typically this indicates some blockage(s) in the transition jets.

I suspected as much. Another carb teardown is in order. Thanks