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YES.  Great link. Fantastic. I would be singing hymns for those folks, not taking them to task because of the anchor text.  Write to them and say THANK YOU!  Its PERFECT!

That's correct. Yeah, the worry is (or was) that the old post, even though it was 100redflags.com, because it was sitting on Tumblr, would necessitate some sort of action in order to retain whatever equity was built in that content. If it's as easy as just making sure those old URLs are 301'd, and I can do what I please with the Tumblr content, that's great news. Thanks to you both for the prompt responses. Really helpful and much appreciated.