According to the SWP's inventory of its own Internal
Bulletins, there never was printed a "v04n04" internal
bulletin.  It appears they goofed when putting the
number on the fourth issue of Volume 4, and numbered
it "number 5" instead of "number 4".   There were only
four issues of the Internal Bulletin published in
1940.   ---marty 
 Director, Riazanov Library digital archive project

 (with thanks to David Walters, Director of Holt Labor
Library who pointed this out to me)