Before V9 was out I had a nice Mr. Big-era patch using the Euro2 sim with an active tone stack. Since Euro 2 was completely remodeled, it doesn't work all too good anymore.
Anyway, from what I 've asked Paul back in a clinic I played alongside with him (he used to allow the organizers to invite 3 people to jam with him for like 5 minutes) in 2003, he was using a Laney GC30 (UK GC30) into matching cab (4x12 75W or 4x12 T75 should get you close on the Axe), a Boss DD-3 delay pedal on the loop and a green stock Ibanez TS-9 on the front for lead boosting. He's mentioned using a capacitor on the volume control to keep brightness while lowering it, and he also only lowers the guitar volume for clean and crunch.
Having played through his rig at the clinic, I can honestly tell you though that 70% of the sound comes out of Paul's hands. I didn't get anywhere close to the tone he was getting with HIS guitar and HIS rig.
Personally, I'm more into his ADA tone, but will give a try on coming up with a modern Gilbert patch for you.
Best,
Alex