They should fit, but you're right: you'll need to make a collar. I made 2x6mm MDF collars. One for the back of the speakers, and one for the front of the pods, then screwed em together.
Not the clearest of descriptions, but it can be done.
It was 6/10 on the ball ache scale due to cutting, retrying, re-cutting, retrying...
Your dealer is a git