Naval 40mm bofors vs ground versions

The gun and cradle are basically the same.  The difference is in the mount, being either the stationary mount of the mobile mount.

You can see both here (naval mount on the left).

Thanks I was thinking that was the case.

Naval mount--usually--had power travers & elevation and computing sights.  Rhat latter depended upon the Navy, the vessel, and such factors.  USN Bofors  used a computing sight on the Mk 51 director, which was separate from the gun mount.  The gun itself had iron sights.

The naval mounts that I am familiar with are considerably different from the mount on the left. For the larger ships they usually were twin or quad mounts. There would be an ample platform behind the guns for the loaders and ammunition passers. There would be seats for the pointer and trainer as well as handwheels to move the guns. And as CapnMac points out there were also iron sights for the pointer and trainer. The gun barrels were replaceable. We had a rack of spares in a ready service room near the guns.