hi, I don't know if it helps and how to make this constructive But…
I installed 10.9 on a partition, having become 'wise' over the many years. This gives me the opportunity to testrun the Os and to see if there are workarounds.
In this case I found one and it is relatively simple:
Because I have a partition on the same drive, I still have the full install of ML. Now, in the library (main and personal in divers folders) the drivers are stored. What I did is copy/paste the whole folder and replaced it in the 10.9 location. Result: it works like before.
Point is here: the software (drivers) just works, it is just the installer I guess hat does not work.
Hope it helps?