I have a Prestige Hi Dome Pressure Cooker which is about 30 years old.
I have replaced the seals many times over the years.
It has given good service.

Somehow, it is not coming up to pressure.
I have helped it a bit recently by holding the top down, until the
pressure pushes the top up and off it goes. This no longer happens.

The pressure begins to build, and then gets released at a point around
the handle.

I have noticed that the spring loaded nib (what word is accurate to
describe the thing?) located in the handle, is slightly worn. (The nib
pushes against the rubber seal and is about twice the width of the
outside of the seal.)
Is this the source of my problem?
Or perhaps it is the spring which keeps the nib in place? ie getting
stiffer, or more bouncy over time?

In either case, is it a new handle?
Or perhaps it is something else entirely?

If it is a new handle, where in the uk might you suggest I look?

thanks for any ideas / help W