Learn something new each day. I agree, Stan- your gun shown, the receiver lines have more "flow" than the rather "boxed" look of a Nitro Special.
My first 20 gauge double was a Nitro Special- 28" barrels- as I recall, it had the same numbered chokes as on my 12 Ithaca NID 2E grade. It had a single non-selective trigger, always firing the right hand barrel first- and I shot a fair amount of grouse and woodcock with it. I used a slip-over stock pad to get the LOP I needed- great gun, and you could use it in the thick cover and briars of good MI grouse cover- and not worry about getting it all marred up. A true "working gun" that I shot rather well.