I agree that there has never been a completely free market economy, and submit that there never can be. But that wasn't the topic.
I think that you do not want to acknowledge the concept of externalization. If so, then you obviously can't explain how Classical Liberalism deals with it. I think it deals with externalization of economic costs by refusing to acknowledge that it exists. Therefore, I can see how you might well be a Classical Liberal.
BTW, a Classical Liberal has virtually no relation to a Contemporary Liberal, in case anyone was wondering.
“You never change things by fighting the existing reality. To change something, build a new model that makes the old model obsolete.” – R. Buckminster Fuller