Over at Moonlight Detective/Beneath the Stains of Time, a really terrific review:
‘a fascinating, time-shattering detective story with an excellently positioned and executed impossible crime, but even more impressive is how beautiful all the plot-strands, decades apart, interacted and were pulled together – proving that murder can be a fine art. Highly recommended!’
http://moonlight-detective.blogspot.com/2019/09/the-gold-watch-2019-by-paul-halter.html