Tool I used to repair my System Audio 1750 and center tweeter element.

Holes need to be drilled out afterwards. ( 1.5mm ) out the holes and then sand the tool smooth again. ( There is an 0.3mm thick layer below all the holes to make it able to bridge it in air.)

Fusion 360 file is included so its possible to change dimension to fit your tweeter if needed.

Consize is the size where you want the edge of the tool to lay against the tweeter.
Conedepth is how much the tweeter extrudes from the place you intend to place the tool.

VacumSize1 is the diameter where you insert your vacuum
VacumSize2 is the diameter the length of Vacumdepht inside where you insert the vacuum, to give it cone shape.
Vacumdepth Where Vacumsize2 should be applied.