There was an article in "The Brewer and Distiller" about a year ago that gave some information about the JS beers; they said that the pilsner was bittered to 35 IBU and had a start gravity of just over 12 P.
You have to bear in mind that commercial beers are always a work in progress and that they are getting tweaked all the time to suit market conditions.
From what he hasn't, as what he has said I think Dig might be closer to the source of information in question than the rest of us, I for one arent going to argue with what he has given you to work with.
The bitterness given can be takes to mean a normal bittering hop addition at the start of the boil. When you talk to most brewers they just talk about bittering in IBU's with out bothering to qualify further. It would take an exceptional pallet to work out what was used to bitter any given beer - unless the hop in question was really off the wall, in this beer my first choice would be Northern Brewer, although the brewery could be using anything
The information on the finishing hops is just that, for the finishing hops only.
MHB