There are sites out there that have plain *.vss files
for download and httrack downloads them and add *.txt
instead of the true.. extension.

I tried the v1. oler browser option, tried adding it as a
zip, tar mime or even app.. any suggestions..

There is no unique hard to d/l link like /index.php2@#2k3asd
and it is a plain, visio/file1.vss, file2.vss file3.vss and 
so on...