By chance I found the required screw driver bit for the screws used on Genesis carts. For a few bucks (shipped) I bought one and I was finally able to open up my Elemental Master carts.
I swapped the working circuit board from the beat up looking cartridge case and put it into my the good condition cart of my original Elemental Master that was not working.
Now I have a good condition ‘working’ Elemental Master. If the manual didn’t have some damage from a sticker and a few other minor nicks this set would be like new.
I’ve been meaning to get a security bit for cleaning NES games.
And this is why it’s handy to keep doubles around… even if they seem trashed 😛