What changed in later 40 mm Bofors installations?

Are the proposed 40 mm Bofors guns the same weapons Allied ships carried in the 1940s?

They are described as modified successors, with longer L/70 barrels and stabilized mountings.

A follow-up asks whether proposed 40 mm Bofors guns are simply the weapons carried by Allied ships in the 1940s. The proposed weapon is a modified and upgraded version with a longer L/70 barrel. Stabilized mountings are also part of the comparison. The point is that a familiar calibre and manufacturer name can continue through substantial changes in the gun and its mounting.