After the HP Software Update my DeskJet 9300 does not print anymore

Unfortunately I did the the last upgrade HP Printing Drivers Update from the Mac OSX menu and now my HP DeskJet 9300 is not printing good anymore: no more A3 size sheet, impossible to handle any custom size sheet, very bad printing quality.

THe problem is that the update installed the Gutenprint drivers and not the HP genuine. And the Gutenprint drivers are supposed to support my 9300 but it is not true. After some efforts I was able to deinstall the bad Gutenprint driver but now the latest 9300 genuine HP driver is not installing anymore: the installer seems to work perfectly but the HP driver does not appears anyore on the control panel.

I tried also to have back the old driver looking in the TimeMachine backup for name/library/printers and I did it but the driver is not showing up anymore in the control panel.

Hope not to have to change my perfectly working 9300 just because of a software issue.

Thank in advance to anyone that could help.

Giulio Piovene