Play in steering wheel

Too little + caster can manifest itself as loose steering and wandering at highway speeds.

Find a local alignment shop that deals with trucks.
It could be something as easy as loose tie rod ends

Modern steering boxes generally do not develop play unless they have a serious issue. Could also be a bad tie rod or drag link end. Rather than a Ford dealer, I'd suggest a popular front-end shop that works on trucks. The Ford chassis can (and should) have nice, tight steering if all the parts are right.

There are many threads on this on IRV2.com. In summary, you can put on a steering stabilizer for about $600, I just added a degree of forward caster when I had the front end aligned. Commonly done , cheap, and solved the problem.

I believe the next biggest improvement you can do is to put a rear track bar on it. Also about $600. It will stop the tendency of the rear axle to shift slightly side to side and stop the "tail wagging the dog" syndrome the Ford F-53 chassis has. I put it on myself and very strongly recommend this upgrade.

I think you need to be a bit more specific with the chassis designation.

My C is on a "Ford V10" chassis too, more specifically an E450.
It was helped IMMENSELY with a "non-standard" adjustment to the alignment but I have never seen any mention of that being done to an A.
I found that adjustment in threads on here.

Old rock hard tires (or overinflated) can cause that too......as can worn suspension parts.

The Ford truck "dealer" in Ocala isn't equipped to work on motorhomes.