Thanks Mike, I'd never seen that motivational video before, now I REALLY know what to do.
Warren: Yes, definitely have insulation in the plan, condensation gets pretty bad here and if El Nino strikes as predicted, summer cooling will also be vital to longevity.
Plan is to fasten some battens on the inside, as the walls are paper thin (Great guillotines), then glue/screw a layer of blue sarking over that for standard condensation protection a la house roofing. On top of that a layer of 5mm silver/foam/silver insulation sheeting. As the bottom is open, I'll put a decent top ventilator in get some circulation. Also a towel and waterproof plastic sheet over the mount for backup protection, as I presently do.
Alex: I most definitely won't be going past the string and cotton reel level, and there will be many months of consideration before I even start that!
There's a Powerbox Mini on top of the mount NUC, so I'll be able to keep an eye on summer performance while I'm hiding in my extremely well-insulated totally off-grid house with a cool G&T, stirred not shaken.
Well, that's the plan, anyway
Oh, and my apologies to all spanish and french viewers, I have no idea on how to add diacriticals to my typing.