All, Per the LAN-attached serial thread, here's another cheap Lantronix device:
https://www.ebay.com/itm/123577635191 This is a LRS-2, which is basically a two-port LRS-1, one of their older models of serial bridges. The LRS-2 is nice not only for the two ports, but because it also has AUI and thinnet. No PSU, but it's a typical 12V 1A center positive supply. Thanks, Jonathan