A further update on this to add to the information. A chromebook locally attached via usb cable can print to the Workcentre 3335 straight out of the box - no fiddling with settings other than saving the printer.
The chromebook can print to other (non Xerox) printers over the WIFI and non-chrome devices can print to the Xerox over the WIFI. So the issue is very specifically, the combination of WIFI and Chromebook and Xerox 3335.
The Xerox Workcentre 3335 is recognised by the Chrome OS - it finds it automatically. However I cannot get any print jobs to come through on the printer.
I have tried some of the google tips about trying Generic drivers and nothing works. The Chromebox and the printer are both on the same WIFI network.
We are a charitable organisation with many staff and volunteers using either ChromeBoxes or Chrome Books and they need to be able to print. This is the first of an order of several printers but they will need to be returned if we cannot get the printer to work with Chrome OS devices.
I would appreciate all the help I can get.