Glad to see your post and to find someone with a rig very much like mine. Fortunately the orignal owner, from whom we bought, had kept all the documentation that came with it, so we have the Dewald owner's manual.
Dewald was taken over and I think it was by HWH, but I can't find the post. I contacted the web-site that was in the documentation and got a reply from the new company.
My concern was parking over the winter with the jacks down, as we're "near" saltwater. The reply was to wipe the exposed piston rods down once a week with silicone lubricant "if you live nearer to salt water than 60 miles". I had a good laught at that, as we're about 60 yards away! The houses across the streeet are on salt-water marina waterfront.
I did get some rust patches last year, but they buffed out OK. This year, I'm going to jack it up high enough to get axle stands under the front and rear axles, then retract the jacks. I'll be buying a set of four heavy-duty axle stands specifically for the job.
Frank and Eileen
No longer RVers or FR owners