Had bounceback a couple of times with knives-sweated a bit as something pointy came back at me...spear must be ten times worse..instant kebab!
Never heard of an Olsen, but some of the old throwers can fetch a bit. I have seen a few on the US #### really rack up the $$$. I reckon its worth looking in to-there are some collectors out there in the US- maybe a google might bring some info up?