The two examples of Knox’s work had been on display as part of Knox: Order & Beauty exhibition – Manx National Heritage’s year-long display in collaboration with the Archibald Knox Forum.
The reopening of the National Art Galley in the same space has seen about 170 historical and contemporary pieces by Manx artists, and those inspired by the island, put on display.
The works include an “extensive presentation” of sculpture, and a dedicated portrait space, which features rare World War Two internment art.
Curator Katie King said it had been “an exciting opportunity to look again at the Manx national collection and share more of it with the public”.
“We’ve been able to bring together well-loved works alongside pieces that have never been seen before, while also highlighting the ongoing work involved in caring for and conserving these artworks for future generations,” she added.
The gallery, which is free to attend, is open daily at the Manx Museum in Douglas.