The above lists the Denver areas clubs and can point you in the direction of stamp dealers. You just missed the major Denver area show by a couple of weeks. It will return next year and there you can seek information, sell or buy Christmas seals. Did you notice the word, "sell."
Not all dealers are APS (American Philatelic Society) members, but you can use this to find dealers in you area: https://stamps.org/dealers
You can also get some "value information" by looking at eBay
listings, especially sold, for US Christmas seals.
lastly any documents, letters and the like relating to the items and family connection can enhance value. Oh, for the framed stuff just take photos with you phone. That will be enough for a dealer to know if it is worth your effort to bring in the actual item(s).