If you want an up to date REAL look at african offroad motorcycling in morocco,
Check out the Dakar rally! I t is on VS versus network (the old OLN)
I would look into getting a BUNCH of air filters, some spare spark plugs and for sure points if you don't have an electronic ignition.
and make accommodations for a jerry can. (maybe one on each side-water and fuel) 5 gallons each?
How far you want to modify you 550 depends on how much beefier and more able to handle extreme conditions you want it to be.
Maybe you need different tires in addition to the sproket? Different Tread patternwise
Maybe modifications like what you might find on a CL versus a CB? You could probably get some clues of the modifications Honda made to the CL, SL and XL models of classic Hondas for ways to make your CB more dual purpose. Maybe you need to get handle bars with a cross member for added strength. Maybe make an tuning/overhaul or improvement on front suspension for rough road handling. engine guards/"crash bars" might save you some headaches.
Those are just a few ideas I had thinking about a response to your post. I like the thought of making these CBs more able to confidently tackle grass, dirt paths, and State Forest roads. Could be cool, I say save yourself some money and make some adaptations on your CB550. Let us know how it goes.
Most of the builds going on now are modifying CBs to be more like CRs (caffe Racing style, and old school track racers.)