Steering column stalk switches

I had/have a bakelite castellated sleeve on the MK1 column that I've left on when installing the MK2 stalks and I've just noticed a white plastic lug for the self cancelling pops out of the central switch housing when the indicator stalk is switched but it doesn't come into contact with the bakelite sleeve.
Am I missing something like an additional sleeve/collar ?
I've check with my Haynes (MK1 brown and MK2 red) books but it doesn't help

the indicator cancelling tab is on the steering wheel

Just checked and mine seems to be only part there hahaha but even if it was it won't contact the MK2 switch so it's a MK2 steering wheel or non self cancelling indicators.I might be able to make something up as the plastic ring on the back of the wheel has self tapers holding it in place so I could mount a lug quite easy I'm guessing. (The last sentence there wasn't for you RJ as you obviously knew that but for neebies like me).