Update-time
Since I'm on parental leave at the moment I've been able to sneak in some extra hours to work on this. Lot's still to do but I can at least get a hint of the light at the end of the tunnel.
First of, after vacation I thought I would mold my Vacuum forming plugs into Ultracal. This did not end well though so I ended up handing this off to a guy who promised to assist.
(I thought of making the mold in Alginate and plaster bandages, and I failed to get the alginate to release properly from the plugs which was the cause of my failing)
So, With that off my mind I could focus on the parts at hand. After a lot of further sanding lt was time to start painting the main parts. I have also made a decal-sheet and ordered as transparent vinyl-stickers. Impatient as I can be, and when I got the decal-sheet in the mail I of course wanted to see how it looked asap so instead of cutting the letters in "WATNEY ARES III" individually I instead just cut a square around them and fitted to the outer shell. When I realised that the other way would have been much better, the tape had already set and to remove them would mean i would have to re-sand and re-paint + order and extra set of vinyl so in the end, I told myself that it kind of anyway looked acceptable. Damn you, impatience :facepalm. Anyway, one day i might redo this, but for now, I'll just leave it as is to save time and money.
Anyway, some pictures from the process: