How to properly configure Vlan Translation on an Older 3.10 Onyx OS

We have an absolutely ancient Mellanox switch running Cumulus 2.5.12. This switch routes traffic into it from campus tagged on vlan 492, converts that to the internal vlan of 4092 to route it around our cluster and then traffic routed back out to campus gets re-tagged with vlan 492. That switch is dying and reboots itself every 5-30 minutes. We have a only slightly less ancient SN2700 that we’re replacing it with that runs Onyx 3.10 which we’re trying to recreate all the many rules someone else wrote for this switch on Cumulus but we’re stuck on this vlan switcheroo business. I’ve tried 802.1q shenanigans and we’ve tried making ACL rules to `vlan-map` but nothing so far seems to make whatever magic needs to happen…happen. Has anyone else had any experience with something like this that can offer crumbs of wisdom?