The original 733 had ElectroMechanical instruments for ADI and HSI, no EFIS. Southwest continued buying that configuration forever, I believe, although the 757/767 EFIS became available in the 73 about 1984. The E/M ADI had no way to display RA, as it didn't even have a vs display. Now it's possible somebody retrofitted an EADI in an E/M 733, without a companion EHSI, but I can't imagine why. The most bang for the buck is in the EHSI.
I'm curious as to the operator of such a configuration, and year it might have been.
GB