With a little playing on SolidWorks, I've worked out that by the shoulder being 7mm from the original "front" face and the same diameter as the inner of the sierra trigger, the all-important weight is changed by about three grammes. The trigger is a gentle push fit on the new diamter, and there are also three loctited CSK M3 screws holding the trigger in place. In this instance the missing tooth is aligned with the keyway, so the sensor will be fitted at 90 degrees to the bore centre at the front of the engine, and my bracket (mid-make at the minute) will offer two or three degrees adjustability.
Before modifying it, I checked how much deflection of the outer ring I was likely to see - which would obviously affect the timing. By locking the driveshaft of the lathe and physically twisting the outer ring with an oil filter strap, there was less than two degrees shift. Allowing for the slack in the cam/dizzy drive and the 3 or more degree's stretch in a timimg chain, that's still well under half the fluctuation a distributor drive will offer.
Unfortunately I wasn't allowed to do the turning myself, pesky liability insurance would only let me be present rather than "doing", and I didn't take my camera with me
All I need now is the opportunity to get the rad out, lift the front of the engine and I'll have me a MJLJ-lit 998 Mini
Edit - the rubber isn't as bad as it looks
same design & methods etc etc, anyway yours looks a good solution there, maybe worth getting it balanced on its ownif your engine is already in