Here's a
link to a discussion on the Northern Brewer forums on 90 Schilling. One poster claims to have info direct from ODell on hops (Northern Brewer + Cascade) and malt bill.
Per this poster, the malt bill is around:
75% Pale ale malt
9% Munich malt
7% light crystal malt
5% wheat malt
3% caramalt
1% choc malt
With an OG of 1.054 and 27 IBU of hops. That should get a start on a recipe. I might just add this to my "someday" brewing list, although this time of year I'm thinking about witbier, kolsch, and hefe.