OK sorry, my eyesight ain't what it was...
As you were...

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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.

Clutch master cylinders are both tin cans (0.75), with the same markings, but one is old (original bore), and one is new.

Flywheel assemblies are both MED assemblies, and are the same with respect to the straps and post heights (both need the posts machined to have the spring sit flat). I can’t see that this area would affect the amount of travel to disengage the clutch (there may be different effort requiered, but the travel would be the same), unless the clutch plates were different (with different amounts of crush in the actual plate).

I know you've gone to some trouble to make that set up and no doubt you thought about it for a long time, however I would feel that a modified tandem MC would be better. The modification being that rather than use the fluid within to drive the secondary circuit, extend the secondary pushrod for a positive mechanical coupling. You may have to look about for a suitable MC to base it on as the Mini Based ones would be a bit too small in diameter.

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