Tthe carbs have now enjoyed a relaxing soak in the ultrasonic. I use acetone in a small container (sink at normal level with water) for initial cutting of fuel residue, then put the parts in the main bath with a cap full of "Micro 90" - a labware surfactant that smells like horse urine - for further cleaning. I was surprised to find that the carbs have a heavy (and of course, peeling) chrome plating on the bodies, bowls, mounting frame and linkage.
Finding all three float valve seats eroded is a bummer. Guess I'll need to turn a cutting tool. Already turned a lapping tool, but the pitting is so deep that they need cut first. This will change the fuel height, but the seats in these Amals are press-in, and can be tapped with a drift from the bottom or top to adjust.
Beginning to feel comfortable that I've found and removed all of the RTV, but still staying vigilant. It has chrome rocker covers, and as with most chromed aftermarket parts the chroming poorly done. I this case, the chrome almost "drips" an edge down over the gasket surface interfering with gasket sealing . May have been the reason that the end bolts were stripped, bored and tapped from 1/4 to 5/16, then stripped again. Luckily they only used 1" long bolts giving ~3/16 engagement. But, the holes are bored and tapped 5/16 NF 1.25" deep, so swapping in 1.25" bolts gives enough grab for the speced 6 ft-lb torque. Put the covers on my surfacing rig (just a piece of plate glass with 600 grit spay glued to it) and lapped them. Not all the way down to bare alloy, but enough to knock the interfering ridge off.
Yesterday I needed ~7" of all-thread to use in blocking off the bearings on my RD400c wheels when I take them to get the paint blasted off today. Then I spotted an old aluminum bar in the off-cuts bucket. Turned and threaded each end, saving a trip to the hardware store. The other wheel has the remainder of the one piece of all thread in that bucket. Rubber vacuum hose jambed over the disk mount studs protecting them.