The treaded parts on the wheels were wider in real life and gave a distinct rim to the wheel at the moment they are nearly flush. I suppose the only way to find out would be to give it a go. New wheels are likely to be the best solution and to my mind this would be a big scratch build job.
The Strelets computer rendering is about right. Copy and paste the plan rendering on your excellent comparisons and you see the wheels are more or less right (note in the rendering plan the trail is foreshortened so that will not match up)
I don't think they have to be 100% accurate but the big traction engine wheels were a distinguishing feature of these guns.
Additionally they would be in a pit to increase the angle of elevation of the gun- notice the men in the pit in photo below.
BTW you will notice that the shells for the 6" gun are not so large that they would need 2 men to carry them though the charge would be much heavier and pushing both together into the breech would be a 2 man job.
you’re right, new wheels would be the best solution. But I’ll doubt SR will take that effort (and costs). That’s why I thought about revised rubber tracks. Honestly, scratch building the complete wheels is beyond my skills. And even doing some wider tracks from bendable styrene sheet will include a vast number of tiny bars on the track surface. Maybe I’ll try a cardboard dummy track to find out whether wider tracks would improve the overall look or not.
The broad wheeled appearance on your photo is exactly what I have in mind when thinking about that gun in action. I like the shape of the SR gun itself, but the narrow wheels kept me from assembling my two A001 kits yet. Hope an aftermarket manufacturer will take the wheel challenge without charging a sky high price (even elevated, it is no AA gun )