Martyg,
I was thinking to have that combo originally, but then my BME44 "suddenly became available", so I drop the project. I guess that the Brison will be the perfect engine, not only for its exterior measures, but also, because I heard that is a real soft running engine. Ideal for a plane like this.
I have the same degrees you have. I think the upper wing in mine is -1. Also I have a 3mm wire that cross the upper wing mounting holes, so it gets attached at once, without any screws. I will post a pic later.
If possible, please, post a pic of your Brisson when installed, I will enjoy to see how it looks. Thanks.