I found the source code for some releases before:
httrack-3.44.1

posting here for anyone else who may want this.

<https://sources.debian.org/src/httrack/>

I couldn't find a tar.gz archive for some of the versions this is what I did
instead:

wget --user-agent="downloading source wget wait=3" --mirror --no-parent
--wait=5 <https://sources.debian.org/data/main/h/httrack/3.33.15-1/>

other versions include: 
3.33.15-1/
3.40.4-3.1/
3.40.4-3.1%2Betch1/
3.42.3-1/
3.43.9-1/

Having them posted would be nice but as long as the sources are somewhere it's
OK.
Thanks anyways, 
Merci tout le monde