The PDF title says 1/100, so I presume you are good to go if you print 100%. You can always test by printing out in 'cheap fast mode' and compare them in the light on top with the original Fortezza files.
Raimondo Fortezza is 'AWOL' for quite some time now. Your guess where he is is as good as mine. He might just have moved on and started a new hobby. Knitting, figure skating, collecting stamps of Guatemala from the 1930s or a career as a wedding DJ...
Maybe there were 'permissions' given but on the other hand, these pieces here look very original and so very redesigned they became something completely new. (Besides that, I recall there were voices who claimed that the Fortezza Shuttle in a way was a 1 on 1 copy of the big Betexa shuttle model in shape and parts)
However, the Fortezza and AXM models are very satisfyingly good on their own - and you can reprint them as much as you like!)
I really do recommend Alfonso's (AXM) shuttle to begin with. Its construction method is easier and the result is astonishingly good. I have been making paper models for over ten years now and still struggled with the
Fortezza shuttle when I made it. The shape of the nose section with cabin is really really challenging to get right.
My suggestion to you is to just build more models as they are, before trying on nitpicking modifications like this, it takes time to get them right and to get the hang of how to tinker with them.
Your Saturn wasn't a bad build at all! You are off to a good start.