First, hopefully you now know that you can't blow off a regular oil level check on a Harley like you can on most other vehicles these days. I suggest making it part of a weekly inspection of things like tire pressures, oil level, lights, etc.
Second, what the dealer is telling you actually sounds reasonable for a 2007 CVO110. Many of those engines had similar issues right out of the crate, with severely tapered cylinders and oil consumption problems. However, if you don't fully trust them (I never blindly trust a Harley shop on anything), I suggest getting a second opinion. Take the bike to another shop (dealer or independent) and have that shop also do a full compression and leak down test. If you get a similar diagnosis from a different place, odds are it's correct.
Third, while a good shade tree mechanic can definitely install new rings, odds are you are going to need a lot more than that. Do you have the torque plates, micrometers, etc. needed to check the cylinders and pistons? Do you have a trusted machine shop to bore and hone the cylinders for you? Are you prepared to also thoroughly check the heads, cam chest components, crank and oil pump, etc., while you're in there? If not, then I'd suggest finding a couple shops you can trust and get estimates to handle it for you. If you're going to spend the money, may as well get it done right one time versus a shortcut that doesn't solve the problems. Oh, btw, valve stem seals were also suspect and could cause oil consumption problems.
JMHO - Jerry