For some reason it wanted to open as a .php and not a .pdf. I did get them open later using the techniques George describe. Not very user friendly, but I think that is a function the GBO software and not the PDF that Tarquin submitted.
The drawings appear to be done in french units of measure....millimeters.
Thanks for a posting these Tarquin.
for those who are having problems opening these files here is how to see them.
Double click on the link. If a window pops up asking if you want to open a file called index.php click on save file, then click ok.
Another window will open and ask you the name you want to save to. Under file name should be the default name Index. Change this name to Index01.pdf. under the save as type hit the drop down arrow and change it to All files and click save.
Do the same for the other two files except save as index02.pdf and index03.pdf.
I usually save the type files to my desktop the first time I look at them and the move them later to another folder.
Now you should be able to open the file just by clicking on them, if you have adobe reader installed on you computer.