I am now thoroughly confused. As far as I can tell from reading the PG blurb, it is ok to transcribe the book, provided that acknowledgement is given (in other words, David Wyllie has released the translation under a creative commons or similar licence). I just wanted to know the proper form of words for acknowledging this.
And I've just had a look at Hadrien's Feedbooks, which also has the Wyllie translation. I thought that I could copy his form of words. But he has noted that the translation is by Wyllie and not made any copyright acknowledgement at all. He's not alone in this. There are several other sites which have the book, mention the translator but don't mention his copyright.
My conclusion is that it is (probably) ok to make a version and upload it. But perhaps I had better include all the PG stuff, maybe at the end. But I was hoping to abbreviate it considerably.