I was having issues getting the right tool to open my Enicar Sherpa Super-Divette with the super compressor case. Specifically, Enicar's scalloped bayonet case back!
Rather than keep hunting, I decided to make one in CAD and 3D print it. And it works! One nice thing is that PLA is probably too soft to mar the case - you're likely to crack the tool before making a scratch on your precious Enicar!
I put the design up on Thingiverse if you'd like to make your own or have someone make one for you: Enicar Seapearl Case Back Tool by SFoskett - Thingiverse