The file looks good to me. I'm not sure what to tell you about the black border thing, but here's a bit more info or more questions:
1) What kind of TV is this? Old, or new? CRT or flat LCD?
2) The HorizSync and VertRefresh entries are a good idea to put in there. With modern "intelligent" equipment, these things can be auto-detected with some reliability, but on older hardware, like old CRT monitors, it was possible to damage the hardware if the frequencies were too far out of whack. Better safe than sorry I figure; I suggest get the appropriate numbers (or range) for your TV from the manual or the website of whoever made it, and put those back into the file.
3) I have not tried this so it's only an idea
: On that README page I linked to, in section 16, they mention the "TV overscan" option, which appears to be for enlarging or shrinking the image. I don't know why
one would normally
want to do this, but maybe it could enlarge the image you see and get rid of the black borders??
4) Can you possibly try "COMPOSITE" instead of "SVIDEO" if your TV will work with that? I found I got a crappy picture with SVIDEO, but looked better using "COMPOSITE". Maybe you would too, who knows.
Well, that's all I can think of for now.. Keep us posted about the black borders.. Someone else may have a better idea later.