I've tried what you proposed two times (once using safari and the other time using firefox)
and i only have these two file/folder :

LibFredo6.rb
LIBFREDO6_Dir_34 folder

i don't see these two anywhere :

ZLoader__FredoScale.rb
FREDOSCALE_Dir_20 folder

Thx for the answer!! maybe i'm just too dumb to make it work...
I will try again...
Thx for ur work i'm sure it's great...

i've read all the posts of this thread...
i'm on a macbook pro
mac osX 10.6.2

I've put all the right things in their right place
libfredo6.rb --> plugins folder
lib6*.rb --> in plugins folder

and when i open sketchup 7 i get this :

Error Loading File Lib6Tool.rb
uninitialized constant Traductor::T6

someone have an idea of what is going on ??

and while im here is there a description of what all the script included in the version 3.4 of your library do??

thx to fredo who is really patient and helpfull to all!!