Re: The problem probably wasn't the software...
Since 1991, the official name of the language is Fortran, mixed-case.
A 1980s-era VAX FORTRAN (it was uppercase at the time) program would likely run, unchanged, on at least one if not more current compilers and systems. Intel Fortran, in particular, supports pretty much everything from VAX FORTRAN except for RADIX-50 routines. (I was on the VAX FORTRAN (and Compaq Fortran and Intel Fortran) team for most of my career, and was the VAX FORTRAN project lead for many years.)
I agree with others that the language was not the biggest hurdle. Heck, you don't even need a VAX to run VAX FORTRAN itself, there is a freeware VAX emulator for x86.
Fortran is still a very active language. Fortran 2018 is in the final stages of standardization and plans are being drawn up for the next revision. (I am now the "Convenor" for the international Fortran standards committee.) Learn more at wg5-fortran.org