The Lambda Papers
library.readscheme.org
library.readscheme.org
Compiler Optimization Based on Viewing LAMBDA as RENAME + GOTO
ftp://publications.ai.mit.edu/ai-publications/pdf/AITR-474.pdf
Debunking the "Expensive Procedure Call" Myth, or Procedure Call Implementations Considered Harmful, or LAMBDA, the Ultimate GOTO
http://dspace.mit.edu/bitstream/handle/1721.1/5753/AIM-443.p...
Design of a Lisp-based Processor
http://dspace.mit.edu/bitstream/handle/1721.1/5731/AIM-514.p...
On the other hand, general access could exceed fair use - e.g. the hosted copy was made for archival purposes of a licensee. Or the hosted file could simply be an illegal copy. While hosting at MIT has some correlation with legitimacy in this particular case, it in no way insures it.
Right now, the papers are there for anyone with a web connection. The risk of breaking that far outweighs the benefits of fixing readscheme.