You might want to look at what is used to run VAX diagnostics when the VAX780, and other simulators are built using the current simh codebase.  I’m not 100% sure that it is a VAXPAX but it might be…

From: Robert Armstrong <bob@jfcl.com>
Sent: Thursday, November 10, 2022 2:01 PM
To: 'The Hobbyist DECnet mailing list' <hecnet@lists.dfupdate.se>
Subject: [HECnet] VAXPAX?

  Does anybody have an image of the VAXPAX (the VAX-11 diagnostic pack for 7xx machines, 8xxx, machines, and maybe a few others)?

  I have one, but it’s a fairly old version.  It doesn’t have any of the 82xx/83xx diagnostics and EVRLA doesn’t know about RA70s.

Thanks,

Bob