While surfing through youtube I came across this video which shows a Gurkha unit marching through Whitehall on April 30, 2015, and participating in a memorial service:
https://www.youtube.com/watch?v=n-Dw6VSLNi8
Does this take place every year? i would love to see this in person. In 2014 I visited the Gurkha museum in Winchester, and because the place had so few visitors on that day the museum manager allowed me to take photographs which is normally not allowed.