Plaag, have you looked into the
JG Copyright Registration Records at the US Copyright Office?
Searchable Copyright Records - search by Keywords: Judges Guild
The first 10 search results (of 51 that are relevant):
Sample record:
Each product has a publication date (self-reported, so accuracy depends on company's records) and a registration date for the record.
Zenopus Archives
website &
blog: Exploring the Underworld of Holmes Basic D&D.
Holmes Ref: Reference Sheets for Holmes Basic Referees, also compatible with OD&D plus the Greyhawk supplement