Stromberg Carlson X-21 M4B project.

[Kevin Kuehn]

Originally Posted by Yamamaya42

I can find little about this specific model “M4B” but it IS seen in this reference, http://www.earlytelevision.org/pdf/rider-67.pdf
And I know that the inner core of it, X-21 was used in many other sets, so it should not be that hard to deal with.

Since you're not in a hurry keep your eyes open for a copy of Riders Television 16. There is a PDF available but I hear they were scanned in black and white instead of greyscale. Those higher volumes should be between dirt cheap and free if you can locate one.