First thing is this; Do you have any dimensions and weight of the device? with a Belgium fuse (?). The body appears to have been machined, via the concentric circles all around the bottom portion. It would also seem to be a "green" colored smoke grenade if there are any holes in the body plugged up or not. The other type of smoke grenades that appear identical to this one all have pull-friction ignition using the old German "Pull Friction" ignition. I am seeing all that have been showing are have a colored stripe running around the grenade at near middle. I have one in my books that has a brown body, red stripe around body at near middle, friction igniter with blue cap and appears to be slightly larger than the other one being shown which has a light brown colored body, with a white stripe around near middle, and has a German pull friction igniter with a yellow cap on it.
Secondly, is the inside "scored" inside at all? Or is it just a piece of Iron or steel?
Lastly, according to my books and my own personal investigation is telling me is that what you have is possibly a "smoke grenade, DA60, Czechoslovakian" For what it is worth.
V40