Origina model 5 alternative spring

[Benelli B76]

These pistols have a large spacer in the compression chamber that gives a loss of about 55 mm that could be used for spring capacity. I found an old worn out spring with more coils that works but I can't identify it. Has anyone else used a longer alternative ?

Baz

[Benelli B76]

Adding an extra piece of counter-wound spring on the spring guide end to see how it performs.

Baz