Mike-

I think that the *value in difference* that you can take home -- the *good news for you* -- is that you can hunt with the CSM 20-bore SxS in your 'no centerfire rifle' season.

If the game warden walks up to you (and you're hunting with one of those nice little guns) in the woods with a 'whatchya got there?' inquiry, you can drop a 20-bore shotgun shell in the chamber and touch it off for him.

I've had this conversation with game wardens (on the telephone) from states where there are 'shotgun only', 'no centerfire rifle' seasons. Explained what I had and that I'd like to know if I could hunt their states with my bore-rifles. What it came down to was whether or not they'd be able to chamber and fire a shotgun shell in the chambers.

Call your game warden and have the conversation with him.
Get it straight from the top.
I'm guessing you'll be able to hunt with the CSM 20-bore.

At the end of the day, we know the distinction.
What may well be available for you is the opportunity to hunt with an affordable gun that fulfills the double rifle style and function.

Cheers
Tinker