WW2 Japanese artillery shell fuze / firing pin

Can anyone help me identify this WW2 Japanese artillery shell fuze / firing pin?

My father (4Corps, 14th Army) told me he found the dud shell alongside / under his truck in Burma in 1944/5 and souveniered the fuze. The firing pin was faulty and jammed.

My own reserches have not so far helped me identify it.

[AlecG

 

http://www.scribd.com/search-documents?query=Japanese++Ammunition



Japanese Ammunition manuals/phamphlets

 

I took these photographs thursday 15-05-14.

 

Looks to be a Type 88 from a Japanese 50mm "Knee" mortar
http://inert-ord.net/jap02h/knee/index.html