I havent handled an ORIGINAL Howdah, so I cant judge weight. I have a couple of the Pedersoli 20ga guns. They are hefty but Im not sure Id call them too heavy. By example the Diablo IS too heavy, (not to mention the grip shape is atrocious).

I "think" its also balance issue. Balance the weight of the total gun with the weight and length of the barrels AND the shape and angle/grip shape. For what its worth The Pedersoli BP guns could benefit from a better grip too. I couldnt change the grip on the Pedersoli BP so I shortened the barrels to give it better balance.