Yeah unfortunately that part number is only for the slip ring and it is compatible with the e89. I can also assure you, and others, that the e90 stalks ARE compatible with the e89 as well. So this can only be down to a faulty set of stalks and not a compatibility issue here. I've done a lot of cross-referencing and superseded checking on all possible combinations for these so you can get the most economical way to do this mod.
I would put up a list of part numbers, but a lot of sellers just put the slip ring number which doesn't help.