Ed,
After examining thousands of shotguns of all types, including the top makes of every nation, I found that there are some common characteristics in what contributes to good handling. With the shotgun taken down pick up each part and hold it from the point you hold it when mounting. So you hold the barrels where your hand would go when picking up the assembled gun, hold the stock and action assembly from the grip and so on.
The more pronounced the tendency of each individual part to swing towards the center, the better the handling of the assembled gun will prove. Conversely the more sluggish, or absent, this tendency the more likely it is to handle indifferently. This test has proven more reliable than balancing at some point of the assembled gun. Any gun will balance at some point along its length, this in itself does not say much for the handling in practice.
As for the finest handling gun I have come acrosss, it is a single barrel 12 gauge sidelock Lang. Yes single barrel sidelock, it has one lock on one side and an escutcheon on the other. You can see it here:
https://gunandknifeclassics.gr/joseph-lang/
