Frankly, I think it is impossible. Many typical Baroque registrations just will not work on a Willis. I have the Hereford. In this case, the clarinet is just to soft and to friendly. You need a louder reed, but the Trumpets are to round.
The best is perhaps to combine a Trumpet with a stop at 2 and/or 1 1/3, you may use the octave couplers or combine a 16' Trumpet with a 4 or 2 2/3. This will make the sound a bit more edgy.
Another option could be to use the tuba, accompanied by part of the powerful principal chorus on the Great. In this case, you just decide to leave the sound ideal of a French Baroque organ and to take advantage from the strengths of a Willis.