File:United Thai Navy Film Production (1966, V2).jpg

Licensing
According to https://legislation.gov.uk/ukpga/1988/48/section/15A/, the United Kingdom follows the rule of the shorter term, meaning that the duration of copyright granted to foreign works is limited to the duration in the country of origin except for works simultaneously published in the United Kingdom.

This photographic work, audiovisual recording, motion picture, sound recording, or broadcast work, is now in the public domain in Thailand because it is a photographic work, audiovisual recording, motion picture, sound recording, or broadcast work and at least 50 years have elapsed since its first publication or it was not published within 50 years of authorship.