Ubuntu 18.04 does not longer support the Nvidia-304 driver

I have an older 32b Dell M70. It was running 16.04 fine but I had the bad idea of upgrading to 18.04. Everything went fine except for the display resolution, the screen has 1920x1200 max but it is not getting more than 1280x1024, that is highly distorted. Under 16.04 it was using the proprietary driver Nvidia-304 that is not longer supported in 18.04. So I enabled the graphic-drivers PPA and that driver appears to be available. However when I attempted to install it I get the following:
Code:luka@falu:~$ sudo apt install nvidia-304
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
nvidia-304 : Depends: xorg-video-abi-11 but it is not installable or
xorg-video-abi-12 but it is not installable or
xorg-video-abi-13 but it is not installable or
xorg-video-abi-14 but it is not installable or
xorg-video-abi-15 but it is not installable or
xorg-video-abi-18 but it is not installable or
xorg-video-abi-19 but it is not installable or
xorg-video-abi-20 but it is not installable or
xorg-video-abi-23
Depends: xserver-xorg-core
E: Unable to correct problems, you have held broken packages.So I attempted to fix it under Nouveau doing the following. I had an old xorg.conf set by Nvidia (under 16.04) and I copied what I thought were the relevant lines, please see the original:Code:# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 331.20 (buildd@komainu) Mon Feb 3 15:11:14 UTC 2014

Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "InputDevice"

# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection

Section "Monitor"

# HorizSync source: edid, VertRefresh source: edid
Identifier "Monitor0"
VendorName "Unknown"
ModelName "Seiko/Epson"
HorizSync 30.0 - 75.0
VertRefresh 60.0
Option "DPMS"
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "Quadro FX Go1400"
EndSection

Section "Screen"

# Removed Option "metamodes" "nvidia-auto-select @3840x1200 +0+0"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "nvidiaXineramaInfoOrder" "DFP-0"
Option "Stereo" "0"
Option "metamodes" "nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSectionSo I copied the lines into /etc/X11/xorg.conf.d/20-monitor.conf relevant to the screen:
Code:Section "Monitor"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "Seiko/Epson"
HorizSync 30.0 - 75.0
VertRefresh 60
Option "DPMS"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1920x1200" "1280x1024"
EndSubSection
EndSectionThis didn't solve the issue. I also added two lines to /etc/default/grub:Code:GRUB_GFXMODE=1920x1200x24
GRUB_GFXPAYLOAD_LINUX=1920x1200The resolution is still stuck at 1280x1024 - My question is: is there anything else that I should be doing?
Many thanks in advance.