I have looked online a little, and can't find a pronunciation for Goffriller.
I am naïve enough to think that it might be pronounced as "Goff - rill - er," but then I start thinking about other words and wonder if perhaps the "ill" is pronounced as in "tortilla" and the "er" as in Auger. That would make if "Goff - ree - yay" (or even perhaps "Go - free - yay").
And then of course, there the question of which syllable is accented.
I am giving a speech about virtual instruments, and I want to mention this one, but I want to make sure that I pronounce it right!
With all respect to people that pronounce german words right (I am german) I think pronouncing Gofriller in a germanic way would be too much of an honour. Even though Matteo Gofriller was born in Brixen which is in a part of Italy with lots of germans.
But whenever somebody talked to me about Gofriller string instruments they were pronouncing it in the french way that has been indicated in the OP. Maybe I am wrong, perhaps an italian could answer this most competently.
My only issue with using the French "-ay" ending is that the word is of Germanic origin, and the actual person was Italian.. netiher of which language uses the "-er" ending to be pronounced à la française "-ay" (é).
If it were pronounced in a germanic way, the "-er" ending would be a lot closer to "air" in English, with a gutteral "R". It's a sort of diphtong in German, almost "ay-ah(r)".
Ya know what?
I'd say you won't have any issues if you pronounced it "Go-Frill-Ur" à l'americaine.
I have to go along with the double l as in tortilla and the french pronunciation of er. But the initial g would be as in "enough". The o would be as in "women". I think the Barbara Walters pronunciation of the r would be appropriate. And it would use the Italian pronuciation of the i. So the correct pronunciation of Gofriller would be "FIHF-wee-yay."