Is the fuel pressure regulator permanently set

[4cambob]

I have been trying to trace an issue with my carbs flooding and I think it may be too much fuel pressure,
But looking at my pressure regulator it seems that the adjusting screw on top has been "stamped" in it's set position.
I can't rotate it and don't want to apply excess force.
Does anyone have any experience of turning this.

[abarth4]

Here is a link to an Alfa bulletin board thread that discusses adjusting this Fispa regulator

https://www.alfabb.com/threads/how-to-a ... or.568689/