I really think it should work. The manual says this:
Touch “AV INPUT” in the SETUP menu.
Each touch of the “AV INPUT” changes the
settings as follows:
• OFF — No video component is connected
• VIDEO — External video component
• M-DVD — DVD player connected with RCA
cable
When a DVD player is connected with an AVBUS
cable, do not select “M-DVD” or else no
picture is displayed even if you select S-DVD.
I have tried it, and when set to M-DVD, the M-DVD function in the AV Menu is still dimmed out as though it's expecting an IP-Bus device. This tells me that an IP-Bus device mapped to M-DVD can still send its video over an RCA cable if the AV INPUT is set to M-DVD.
Although worst case scenario would be you have to chop up an AV-Bus cable and splice a composite RCA video cable into it to make it work, but I really think it won't be necessary.