I did some research on this. There are still a couple of Fortran compiler developers around from the DEC/Compaq days! Here's what I learned.
The premier version of DVF was 5.0, and the premier version of CVF was 6.0. No “Compaq Fortran Runtime 1.1” was ever done.
Not quite what you wanted to know.
Furthermore, the runtime never had its own ECCN, as it was not sold separately. If you needed one, you'd use the same as for the compiler product, which is 5D992.
From the DEC Wiki page::
As of 2012, decades-old hardware, including PDP-11, VAX and AlphaServer, is being emulated in order to continue benefitting from software written long ago; funding for this is scheduled to last at least until 2030.
Why would they continue to use PDP-11 programs are any of them written in Fortran?