Yep that is exactly what it was intended for. It could have worked in the 320 line mode as well, but was predominantly for backup in case the color hassleblads failed.
This is the document regarding the adapter - just like you say, very low tech but very effective.https://dl.dropboxusercontent.com/u/4960558/A11_color_test.pdfThe top color picture is from the adapter method and the bottom is a regular 35mm reference color photo.
Sure, not bad for stills. It's when things move that stuff starts getting weird.
And there, raven, is the very reason why I started researching "Live TV From the Moon" and "Live TV From Orbit": I could not get my head around how they got color from the lunar surface, and why the images looked confetti-like during fast motion.