My 1891 Quality 1 sitting next to a circa 1940 Featherweight gun at the Colorado Vintagers Polar Bear shoot here last January. While both are 12s, a regular-frame gun would be a more-representative comparison here, but this will serve. There are some clear differences here, but they aren't as stark as they would be compared to my 1890 Quality 2 gun.

Both guns have the now standard "rounded-front" Fulton barrel lug (the Featherweight's is clearly much smaller), the forend iron is also narrower and seemingly deeper as well on the Featherweight, the breech balls are very different (the '91s are clearly more-angled), and the lower straps are different as well (one screw versus two), the 1940 gun has the now-classic Fulton "flat" bottom of all the post-transitional Smith guns, but notice that the frame geometry of the guns is almost identical (look at where the triggers are set in relation to the body of the action). Compare where the screws are in front of the trigger-guards in relation to the main body frame. They are in identical locations. The "Syracuse" variant of these Smith guns are not (see the earlier side-by-side comparison photographs above here). The trigger/action/stock geometry is noticeably different.

Clearly, the stocks on these guns are quite different as well (a round-knob versus a capped pistol grip) and the more modern gun has fluid-steel tubes (& American walnut).

All of these points are fairly-trivial in the scheme of things, but...they highlight the differences between the multiple eras of LC Smith gun production (in this case, post-1913 guns and the much earlier [nearly 50-years] "transitional" Fulton guns. The Hunter Brothers took the almost "boutique" master & apprentice production process in Syracuse and then scaled it up for a more streamlined (& efficient) process at Fulton. Post-1913, they "streamlined" it even further for true "mass-production" and the guns reflect those changes.