I don't ever recall holding in the MFA rocker switch to try and access the menu, if Andy (Maxitrol) still has that stalk maybe he could try for you. When I briefly had the 872 clocks I had a later MFSW and Zenec HU.
But the stalk would let me run through trip functions etc.
I do recall a member on another forum having a similar problem to what Ed describes with an older RCD300, maybe he can recall this better than I. x72 clocks were very late 2005 onwards, maybe this is why they don't appear in your manual?
What I do know is you can get standard MFSW from ebay.de for as low as €75, it may be worthwhile buying one to swap the buttons, then selling it with your old buttons for the same sort of price?