I got them off of eBay about 3 years ago. Keep an eye out for the books available from this seller here.
@ASTROBUDDY:
Whoa, you own about 11 volumes of those? Amazing!
If I assume that each volume treats 4 or 5 episodes, it seems as NTV published nearly the entire 80's series in book form.
It's really a shame that the site which I posted the link to on page 2 doesn't exist anymore. It actually had each of the book-covers' images viewable.
I just own the two books I posted the scans from.
I actually don't feel like doing further scans, since the books' bending starts to wear out. I think I captured their contents' essence well enough, otherwise one is better off watching the 80's series on DVD.

@Bigdog:
Yeah, the scans here don't really represent the actual images' quality; mainly due to cropping. Scans of bit-mapped images are always a pain in the neck to resize.
Your theory about copying the finalized cels looks reasonable to me. Given the age of the copies I got, I barely noted any fadings of color, which isn't to be taken for granted.
ASTROBUDDY, if I may ask, were you able to pick up your copies in good condition?