I share your understanding. Under the anomalous Peter Pan arrangement, restrictions on derivative works expired (in 2007, after the duration was extended), but

I share your understanding. Under the anomalous Peter Pan arrangement, restrictions on derivative works expired (in 2007, after the duration was extended), but GOSH's royalties continue. It sounds a bit like the situation for songwriters who record their own songs. They hold two kinds of copyrights (one on the songs themselves, and one on the recordings). Initially, holders of those copyrights have extensive control over the songs, but then when the recordings' copyrights expire their control diminishes: https://www.gov.uk/government/publications/copyright-notice-duration-of-copyright-term/copyright-notice-duration-of-copyright-term#how-long-is-the-duration-of-copyright https://www.gov.uk/government/publications/copyright-notice-... (Also not a lawyer)