P-06 Grip Safety shooting problem

[Kiwi]

I have a 70's Mauser and the grip safety is a shooting problem.
If I hold the pistol normally with the back of the grip in the web of my hand - it will not fire

My hand web is too soft to depress the safety fully
I have to modify my grip such that the base joint of my thumb is at the back of the grip to fully depress the safety.
This is weird and unnatural for shooting.

I could build up the safety so the web will fully depress
or somehow modify the safety so a lesser depression will disengage

any thoughts from the forum