Something not right here, getting drip fed info....
Now you say the Edel wandered at idle.
And the engine is 'bone' stock?
Stock engines will have 16-19" of vac at idle, not 10-11".
A stock engine should idle at 5-600 rpm, not 900....
Since this problem has occurred with TWO carbs, & from what you have done so far, I suspect the engine has had a larger cam fitted. That would also explain the 16* init timing [ which is good, not a problem ].
The high idle rpm could be activating the centri curve in the dist, especially if the springs are stretched. This could explain the varying rpm & needs to be fixed first. Check by monitoring the ign timing with a timing light.
One last thing to try: initial timing is at 16*. Loosen dist, engine idling, turn dist slowly CCW; keep going until rpm stops increasing & THEN see what the timing is.
I suggest you try the above & report back.