Help Identifying WWII Fighting Knife (Probably Theatre Ek)

[jriley1520]

Newbie here,

 

I've attached two pictures of my grandfather's WWII fighting knife. Some much appreciated help from the folks over at bladeforums.com, and Frank Trzaska from usmilitaryknives.com has led to the conclusion that this began life as an Ek (which model is still up for debate), and was modified in theatre. The serial number suggests it was one of the earlier WWII knives, but there is no John Ek markings on the blade itself. Any help/insights/suggestions/guesses regarding this knife would be appreciated and encouraged. My grandfather lived in New York state and was stationed in Alaska during the war. Blade length is about 7", handle is about 4". Knife is currently across the country so that is the best I can do for now. I also posted this in the Ek forum, but thought it might get a little more notice on its own.