Frister Rossmann 114 Star tension unit?

Hello

I have been cleaning the above sewing machine and removed the tension unit (no26 in the manual) - it has numbers 0 - 9 on it.

Perhaps I should not have done this as I can not seem to put it back correctly.

Am I right in thinking the the 2 saucer discs need to be back to back so that only the middle parts touch? Or should the saucers be fitted so that they only touch round the circuference?

Also the metal spring retaining cup nearest to the plastic knob with numbers 0 - 9 on it - well this cup has a lug on the side and I am unsure as to which way the lug should face?

If anyone knows I would love to have the answer. Thank you for any help.