Jonny,
I bought the demo pair of SS-M7's from the local dealer on closeout when they were discontinued. They were my only speakers for years, until I got the bug to start building speakers for the fun of it. They still sound good in my garage driven by a Luxman integrated, probably better than anything I build if I'm honest.
A sketch of the driver baffle is attached, dimensions in cm, NOT to scale. The baffle slopes back at 11 degrees as measured both by protractor and smartphone inclinometer. The sides slope 10 degrees (measured on the flat sides, not along the front edges).
If you need more measurements, just ask!
Bill