I think the Rules Cyclopedia is a 90s? version of the original Basic, Expert, Companion etc series in one book. The art is kind of lame in the book itself.
B/X was Moldvay and Cook's efforts and came before the Mentzer Red Box, I have both they are similar but Moldvay assumes you are an adult. I think Wotc is selling a cleaned up pdf of this through dndclassics.com all the classic modules are there too.
Lamentations is a modern retroclone of B/X with a weird vibe check out the author Raggi's site http://lotfp.blogspot.com.au/
he has his Grindhouse pdf with no art that can be downloaded for free.