Someday when I get time I will put a US Army document from WW2 on my website that is all about mothballing engines. But they assume you are taking them all apart and slathering engine rebuild grease all over everything including engine sheet metal, then buttoning it all back up.
I think for most of us, just draining the fluids, install fresh oil, run the oil pump so oil is circulated everywhere at the onset, then plugging every single hole would suffice. If you cover it, which isnt a bad idea, I would get one of those LARGE clear bags and seal it up. Put 50/50 anti-freeze in them and use whatever fittings you need to seal it in.
Since your humidity is about the same there as it is here, I think as long as it's in your shop, covered and tight, considering the above, you will find them in the same shape you put them in 10 years from now.
