In the end it was the module. The replacement I got decided to play up.

I did take the opportunity to tear down the dizzy though, clean it up and set the end float, so the car is running a sweet as a nut now. A nice addition from all this is the Accuspark Blackbox Mk3. It has a nice multispark function at start up (five sparks at startup. You can hear it through the block, its like a welding spark). There's a vacuum pickup on it was well, which would take a vac from the twin SUs somehow. It might be cool to play with that option to even out the idle.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Some modules I have found to be height critical. Relative to the magnet ring. Twice I've needed to pack up the magnets with a plastic washer, once I needed to pack the module up. Chinese made dizzies vary compared to a real lucas 45D, however that was the one which needed the module packed up.
Somebody should put an alignment mark on the module..!

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I think you might have nailed it. I pulled the dizzy down to shim the float that was apparent in the shaft. Once I did that the problem went away.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.