FWIW, here's a fairly recent USA Today article on...
Cuba 'people to people' trips back on track for Americans
Grand Circle is mentioned as one of the approved travel companies.
Also, the official US State Department info...
What Can Be Brought Back
If U.S. travelers return from Cuba with goods of Cuban origin, such goods, with the exception of informational materials, may be seized at Customs’ discretion [Section 515.204 of the Regulations]. Cuban cigars and rum are routinely confiscated at U.S. ports of entry. Purchasing Cuban cigars and rum in a "duty-free" shop at the Havana Airport does not exempt them from seizure by U.S. Customs. There are no limits on the import or export of informational materials [Section 515.206 of the Regulations]. Information and informational materials such as books, films, artworks, posters, photographs, tapes, CDs and certain artwork are statutorily exempt from regulation under the embargo and may be transported freely; however, blank tapes and CDs are not considered informational materials and may be seized. To be considered informational material, artworks must be classified under Chapter subheading 9701, 9702, or 9703 of the Harmonized Tariff Schedule of the United States (for example, original paintings, drawings, pastels, engravings, prints, and sculptures are all exempt.),