There's a little info in the book "The Battle of France Then and Now" by Peter Cornwell.
As Alain said, it should be
N6219. This Blenheim was shot down by Bf109s of 2./JG1 and 3./JG27 between Maastricht and Tongeren in the early morning of 12 May 1940.
No record of loss in the Dutch register, so Belgian side more likely.
Further circumstances of 139 Squadron that day here:
http://content.yudu.com/Library/A14d...sources/29.htm
(you may have to the enlarge the page a bit).
F/O Grey-Smith was captured, other crew Sgt Cyril Taylor (530913) is still listed as missing and is mentioned at the Runnymede Memorial, as is Sgt Phillip C. Gray (580511).
Groet,
Leendert