I think Duke was regarded as a conservative and not a rino. I further suspect that the rinos are mostly clean. Think Snowe, Collins, Chaffee, etc. These are honorable men and women. Not as conservative as we would like, but they are honorable people nonetheless.
Read their "Special Interest Ratings" and then tell me that they still look like Conservatives to you. You can also read their entire voting records at:
http://www.vote-smart.org/index.htm
(Just do a search on their last names.)
People that receive 100% ratings from NARRAL and Planned Parenthood for voting as they want them to can hardly be less than RINOs, IMHO.
However, if you just mean they're "honorable" in the sense that they'll waste your tax dollars and vote for things you find offensive, though won't take any soft money from fundraisers/lobbyists, I can see your point. ;)
And you're right...hardly anyone with an (R) behind their names these days is Conservative enough for me. But that's just me. :)