I don't think VAX emulators were the thing back then. :-) In fact, our target platform was a cluster of commodity DEC Alpha machines running an early version of RedHat Linux for AXP. I know for a fact, that we were the first system that employed Linux clusters in fintech.
This is what Ticketmaster did. Up until a few years ago, and it’s probably still the case, they heart of their reservation system was written for the VAX in the 70’s. When they had to make the hardware/OS switch, rather than port, the went to an emulator.