Hi Ian,
If he sends the form for you to have a psa test I don't suppose you need to wait 2 weeks. Although perhaps he's thinking any effects from the UTI or anything else might have declined by then.
It's common to have Gleason upgraded, mine was upgraded to 4+4. A nine could be 4+5 or 5+4. The former being marginally better.
Negative margins is good although I don't know how that squares with seminal vesicle involvement. Perhaps someone else will comment.
Carry on hoping the reading is an error. I had one strange test which I got retested to get the right result. Although the odd test was at another lab and they advise you to use the same lab.
All the best,
Peter