If you remember, we had ordered a new time of 3D printed battery modules, specially designed to be used with glue on broken calculators back sides:
This version is intended in case of both supports of screw head broken. For any other case, the standard piece would fit better. The repair is also definitive: if it doesn't work or gets corroded, the repair would be much harder!
Here is the body for the standard piece:
The pieces have arrived and we will do some tests during this week end. We'll come back with the results next week!