Already have the zip and unzip packages in the Debian v3 (woody) VM I'm using to run Internet Rex but wanted additional archivers available.
Had been able to do a look up for program/packages like lha & unarj at archive.debian.net by their path names but not by their package names, even though they were showing as being in the woody distribution. After an email to the admin there, that's been corrected.
I'd also forgotten that those packages were in non-free back then. Added 'contrib non-free' to the apt sources line, and was then able to do an 'apt-get update' then install the lha (for the lzh archiver) and unarj packages with no other issue, as well as the unrar and zoo packages.