From everything I've read, and breeders I've talked to, the situation like the breeder listing your lines as something different is a common problem and why most reputable breeders are so, so cautious about who they work with and why they take years to get to know a person before they will share their lines. There's just so many people who through ignorance or selfish or malicious intent are willing to undo generations of work to better the quality of pet rats from the cancer and respiratory plagued (and sometimes genetically aggressive or skittish) messes that herp, mill, and unethical/ignorant hobby breeders have made of them in the last 20 years.
Like I said, your best bet for working with quality lines is to take the steps to educate yourself until you are very knowledgeable in genetics, ethical rat husbandry, and to apprentice yourself to an established ethical breeder with a good reputation for a few years. Good breeders don't exist in a vacuum. It sounds like you are starting to take the steps you need.
Finding a good breeder for the latter is a combination of asking around like you're doing, and working to become a part of the larger rat community. The Goosemoose community is a way to start. Determining who's good breeders, is a process of patience and getting to know people as you know. Though I will caution you that you will get a lot of flack and blowback with your current breeding practices. I've watched them long enough, and have seen what is considered good breeding practices by the central rat community at large. Your best bet is to be patient, keep a low profile, and most importantly continue to be honest and willing to learn, learn, unlearn, and learn. Me, I feel anyone can learn as long as they are willing and patient.
I'm sorry you accidentally brought a disease into your colony. That's always tough. I'm glad no one died though! That's common with some of the worse illnesses like sendai etc. If you haven't already as a result of this experience, one thing you'll want to be sure to do is to set up an offsite quarantine location to keep your incoming rats to keep them for the 5 weeks minimum duration suggested for breeders before introing them to your colony.
Some of the better breeders I've seen are with good informational websites:
Blackwolf Rattery (SoCal)
Phoenix Gate Rattery (Georgia)
Spoiled Ratten Rattery (Missouri)
There's so many more, but those pop off the top of my head. Check out their websites. I go back to their sites and am always learning more.