Okay, confirmed accelerator pump works.
Disconnected the vacuum advance and symptom gets much worse. Engine stalls with throttle open, which makes sense.
Checked timing again and set to zero advance. Engine sputters and just about stalls with throttle open. If opened slowly its more well behaved but not perfect.
Checked vacuum at advance connection (10-15 inches).
Engine vacuum is in the green (I forget the value) and starts/idles well.
