For a printer like an Epson MX80 an esp32 should be enough to share the printer on a raw TCP interface (AppSocket I think the protocol is named) on port 9100. It is supported by Windows and CUPS.

Very easy implementation as it essentially it just forwards the data to the printer. Since it's a raw interface you need the proper driver, but luckily Epson provides a Windows 10 driver for the Epson MX-80 (!) [1] CUPS doesn't have driver for the MX-80 but it has a number of generic Epson drivers and my guess is that one of those will work.

The most difficult part is probably the parallel interface (unless you have a printer with a serial interface in which case it will be much easier)

[1] https://epson.com/Support/Printers/Impact-Printers/MX-Series...