Modifying a B&W TV for composite video input

I have read a lot about the SWTPC TV Typewriter, and I am interested in how people modified a black and white TV for a video monitor. I have an old black and white set that I thought would be fun to modify for use as a video monitor. Now, granted, I don't really need another composite monitor, I have plenty of old Apple monitors that will do the same thing, I just thought it would be fun, since it would be a challenge to find where to input the signal and how to do it. I found the PDF of part of the SWTPC TV Typewriter manual on a web site, and it explains the process, although not in great detail, and references a circuit diagram of what needed to be added, but the diagram is nowhere to be found. Does anyone have any instructions or hints that they may be able to give me? Has anyone done this before? Any advice would be appreciated. Ian Primus ian_primus(a)yahoo.com