http://www.smart.net/~rlhamil/vbisam-magic.txt
is a magic file (for the "file" command) entry I put together.
I've  only used the 64-bit part, but it should be pretty straightforward.

It's for the version of "file" usually used on BSD or Linux, not the
simpler vanilla System V version, which has a more limited
syntax.

I hate having binary files lying around without some good way to
guess what they are. :-)