Husky, I am out of date in terms of exactly what Peterson production looks like these days, which lines are made and what they look like.
But the most expensive series pipes were the Deluxes and Supremes, followed by the various Rosslares (Rosslare Royal Irish having silver mounts I believe) and Harp. At one point the Harps had acrylic stems while the rest of the production was ebonite. I think the Sherlock Holmes series had pretty good stems and briar too. I believe all the pipes are factory fit with acrylic now, but I could be wrong. And I have no idea what the various anniversary and celebration models look like. Just looked at their website, and ... man not much there nowadays.