Reddit mentions of Camco Aluminum Anode Rod- Extends the Life of Water Heaters by Attracting Corrosive Elements, Tank Corrosion Protection (11563)

Look into updating the plumbing to PEX (white /red) if possible. It's a nightmare to go behind all the fixtures, but PVC (grey pipes) gets old and if it cracks it's a major problem.

Also roof and window seals, another bane of the old RVs. Make sure they're all good, or redo them. Leaks like that, aside from mold, tend to swell anything water comes in contact with.

Fridge, furnace and water heater - clean everything as best as you can. Burners especially. For the water heater - flush it good a couple times and replace the drain plug with a zinc anode to extend its life. Upgrade them all as soon as you have the means to.

Amazon also has propane and CO detectors. Make sure they're up to date, and put at least a 50w solar trickle charge panel on the roof for your house battery, as the propane detector has the nasty habit of draining it.

Finally, I'd look into upgrading whatever furniture you can. Mostly the folding couch if there is one. Motorhomes like this are / were designed for seasonal living in, and everything inside isn't designed for full time occupancy. Add the fact that it's a moving vehicle and thus subjected to vibrations and flexing. Last thing you want is your stuff to come apart while you expect it less.

Source: I'm on my 4th RV and been through all the crap I'm telling you about 😁