It would be helpful to know the mileage on your 911 and remember, your bushings are 24 years old.
I replaced my bushings (front and rear) about 10 years ago. I put poly-bronze bushings on the front (no noise) and Neatrix on the rear. I am seriously considering putting poly bronze on the rear this winter.
Elephant Racing sells the rubber bushings for your car.
https://www.elephantracing.com/porsche/911/bushings-bearings-for-911/rubber-bushings/