Since X would not start in the default settings, I have downloaded 4.3.0
Binary from XFree86 site and installed it.

The twm screen is implicitly displayed so "mozilla" can be started, but
the Monitor section in XF86Congif file does not show the monitor frequency:

Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection

I want to put horizontal and vertical frequencies here but unfortunately,
they do not seem to be given in the machine specs.
Would highly appreciate it if anyone could let me know those values.

I have successfully set them as follows.

Section "Monitor"
Identifier "Generic Laptop Display Panel 1024x768"
VendorName "Unknown"
ModelName "Unknown"
HorizSync 31.5-48.5
VertRefresh 40-70

Thank you for your advise.