Well, what was the exact rsync command you issued? Did it take long enough to complete as to indicate it really worked and stuff was downloaded?
Try going into the directory you issued the command from and do "find . -name *.t?z" and see if it brings any results
If you don't remember the directory you issue the command from, try doing "find / -name 4.7.3 2> /dev/null" and see if it finds the directory for you
On a side note, for some reason I tend to prefer using wget to download this kind of stuff...
In this case, you would do
wget -r --no-parent http://alien.slackbook.org/ktown/4.7.3/x86/
or, if you have a 64bits system,
wget -r --no-parent http://alien.slackbook.org/ktown/4.7.3/x86_64/
Remember that the content will be downloaded inside the directory you issued the command from. Also, wget will download into a folder a hierarchy such as alien.slackbook.org/ktown/4.7.3/x86 in your current dir