Gadget.
If you don't get the needed technical drawings for machine an adapter, an option:
First, installing (the non available yet) "X upgrade" that allow Gladiator Mk.II "vanilla" use removable grips (SCG Kosmosima, MCG) remove Gladiator twist rudder.
So easy (and probable cheap) way to install SCG Kosmosima grip in Gladiator Mk.II "vanilla" is 3D print a simple one.
Open SCG Kosmosima grip, measure the piece that fit the 3 pin connector to grip shells, but ignore the 3 pin connector part, measure only the pole above and the fixation tabs, see highlight in this picture:
Then draw this piece in CAD software adding a section for fit over Gladiator pole, similar to this "Thrustmaster FCS/TopGun B8 grip adapter for MS FFB2 base", and 3D print.
https://www.shapeways.com/product/4TKNS ... d=63516898Cut the 3 wires of the cable that goes for the 3 pins connector (visible in picture above) - or use a new cable with compatible connector (probable JS3) and replace the original piece inside SCG Kosmosima with this new 3D printed piece and fit over Gladiator pole, solder the 3 wires or use an small male/female 3 pin connector.
EIDT _ Looks that is not need cut, neither replace seems Gladiator base cable use the same connector:
Mechanically the installation is done and is reversible, if want return SFG Kosmosima for their original form, for example for use in Gunfighter base, just need solder the 3 wires case cut instead use new cable.
But for your new joystick work
you need a new firmware for Gladiator Mk.II "vanilla" with support for SGC Kosmosima grip, don't know if VKB made this available, so check this before start.
BTW - Having success announce the removed KG-12A grip of Gladiator in Combat Flight Simulator(e.g. IL-2) forums, some guys want this "lookalike" Luftwaffe grip for use in Warghog or VirPil bases (what require redo their internal wiring for CD4021 Shift Register).