You can try to capture, using the capture url feature of 
winhttrack ('Add URL'/'Capture URL') to get the first login 
(http://archive.tjgy.com/auth/login.html) page, and them 
copy/paste the desired link sections (example: 
<http://archive.tjgy.com/f/Usenet_unsort/alt.binaries.picture>
s.monsters/index.html). 
BUT use filters to limit the scope of the mirror 
(Options/Scan rules), such as
-* 
+archive.tjgy.com/f/Usenet_unsort/alt.binaries.pictures.mons
ters/*
AND use bandwidth limiters (1 simultaneous connection, and 
reasonnable bandwidth limit) not to clobber the site.