In my opinion the 19.5" dual wheels were a good choice because they fit (with few exceptions) over the large rear drums, also availability isn't bad, not expensive you just have to look a little for used ones.
New ones are available as part number 29015 on page 27, this Accuride catalog
http://www.accuridewheelendsolution...ev-2-Accuride-Wheels-Product-Catalog.pdfThey don't look good.. not bad, but nothing like the original 18" wheels do, looks is not a selling point for the 19.5 duals.
In general 19.5 tires single or dual are tall, the 8R19.5 tire you're likely to use is 31-32" tall. This helps with road speed which is already a challenge with low axle gears.
They're also heavy duty, they're a real truck tire with good load ratings, not passenger vehicle tires. You can't buy a light duty 19.5" tire
They last a long time, wear well.
I have switched from both 7.50-17 and 18" tires on single and dual 1 tons to 8R19.5 tires and both seemed to ride smoother, notice the pot holes less.
I have not tried modern 16" tires on either so don't really have comparison or comments on that.
19.5" single wheels are a great option, tubeless, taller than 17" originals, same style/looks of wheel, can even fit original hub caps. Only trouble is they're not made new in the original style/look that I know of, and they're hard to find. You can however buy new ones that look different.