Don't know if there are any project on home build Ethernet card for the PDS slot ?
Not that I know of, but the PDS slot in the LC475 is using the interface from the MC68030, it's identical to that in the LCIII and backward compatible to the shorter, less capable slot in the LC and LCII.
There is a modern Ethernet card for the SE/30, the SEthernet/30. I have reworked my own version for the IIsi (see here).
I expect it wouldn't be very hard to do a LCIII/LC475 version. The slot is physically wired completely differently, but logically all the MC68030 signals are there so it's just a matter of doing the PCB.


