Been a long time since i was on this forum. I still use these converters and they work great.
Yes, the UD board from the RA6 chassis is EXACTLY the same pinout wise as the UD board from the DA4 chassis. (Checked the Service Manuals Schematics)
Though, like described in following posts, you will need a buffer to boost the component cable signal level with a buffer like the ST TSH343 like i use in mine.
Here is the manual of the TSH343http://www.st.com/web/en/resource/technical/document/datasheet/CD00079537.pdf
Since it's been a while i have forgot how i connected the resistors to that chip. I will post back soon with complete wiring diagram of buffer.
To answer your question directly : Yes it will work, but image will be dark. Advantages of this UD board is that there is no left shift.
These converters work connected to HDMI/DVI outputs of a PC too (need to set it to 1920x1080i (30hz) or 1366x768 (1280x720 may work).