Hello Mephitus,
I had assumed that an RM3E was an RM3E, but having looked again at your Imgur pics I can see that this is not the case. Having said that- the handle must come apart somehow, because it was assembled in the first place. It does look more like my RM2 handle (which is missing the strain relief) and I had to repair that when I acquired it, although I cannot recall how. Attached is a pic of the 'other' type of RM3E, and the only pic I have of my RM2 dismantled.
Regards, BT