Bother...

[dxmachina]

So, the slippage I noted in the rear derailleur doesn't appear to be an alignment issue, but rather a problem involving the chain and the lower cog on the derailleur arm. Will attempt to clean both the chain and the arm later in case it's just a grit build up, but I'm not hopeful. I can't actually see any grit build-up that might explain it. The bike could use a wash, anyway.

Meanwhile I'm off to East Bay with the Univega. Have swapped saddles, so at least it should be a comfortable ride. Note to self: Remember to push the timer button.