I believe the earlier Landrovers (and nuffield tractors) had the same socket on the dash.
Are you looking for 'period' accessories? (obviously not a period phone charger 🙂) ... if so here's a vid of an inspection lamp from an old landrover .... probably available from ebay if you can wait a bit.
If you want the socket to power modern accesories then you can still buy the plug to suit the socket and fit it to whatever you want.
