After dealing with this for over 2 years I am no longer shocked (it also took them over a year to release proper 64 bit drivers when OS X 10.6 was released). I am however disapointed that this has not been fixed yet with either a fix to the driver (which obviously did work prior to 2.7.9) or a fix to the 7545 firmware.
As for Kimzi's suggestion, I did try looking into it. On a Mac the ppd files are actually contained within .gz archives. If you extract the one for "Xerox WC 7545" and then open the contained file with a text editor it does appear to be a ppd file, but I was unable to find anywhere to manually "hardwire" the accounting code into it. This Mac ppd is quite different than the ppd on a Linux system, which I have edited before and used to print successfully from Linux systems. If anyone figures out how to get that working I'd be interested.
In the meantime, I was able to come up with my own workaround. It isn't very pretty and definitely not standard procedure but it is working so far. So I figured that the driver installer for Mac is basically a script that copies files to the proper Library folders and sets permissions on them. So I decided to try and do it manually. I installed the drivers (2.7.7) on a Mac OS X 10.9.4 machine. I then went through the Library/Printers folder and manually copied out all the files that had been installed by the driver installer. This includes one folder "Library/Printers/Xerox" (copy the entire Xerox folder) and then all the "ppd files" (actually .gz files) that start with Xerox from "Library/Printers/PPDS/Contents/Resources". Once you have those take them to an OS X 10.10 system and manually copy them back to the same locations, copy the Xerox folder to "Library/Printers" and put all the .gz files in "Library/Printers/PPDS/Contents/Resources". Both these actions will request authentication as you are copying files into a system level location. Once the files are there you can go to the System Preferences, Printers and add the printer manually as an IP printer, make sure to select the Xerox Workcentre 7545 driver (which should clearly show that it is version 2.7.7, or 2.7.9). When you click add to actually create the print queue it will pop up an error saying that the driver file permissions are incorrect and that the system would like to fix them for you, click ok and then authenticate the action. This will fix the driver permissions and make a functional print queue. You will need to go into the options for the print queue and select the proper finisher and hole punch for your copier. The OS X update system will become aware of these drivers and start offering updates. Make sure to go into System Preferences, App Store, and turn off any automatic update install settings.
There is one drawback to the above workaround, or any workaround that involves using the older driver, and that is that the old driver only supports whatever Xerox Workcentre copy machines were in production at the time. If you have an environment that has more than a few Xerox machines and get a new model that was not available at the time of the 2.7.7 or 2.7.9 driver then you will not be able to create a proper print queue for the new model copier.
