Missing Alphabets

As a former native German this task was "right up my alley". Sadly There is'nt really that much to work with. Darn difficult letters left...

As I understand you want options I thought I'd give you some, but be advised that I've already ordered them according to my preferences (which you naturally need not heed...

Always:
German (English/Finnish) [submitters note]

C
General note: C is not easy as it is mainly a letter used in borrowed words in German. Sadly none of them have clear Nazi connotations.
Chemie (Chemical/Kemia)
Chinese (Chinese/Kiinalainen) [you already have the Jew, so another "untermensch" race might fit]
Christus (Christ/Kristus) [Depending on whether your moon based nazis practise religion]
Chef (Boss/Pomo) [always a useful word in authoritarian hierarchical societies]

I
Infanterie (Infantry/Jalkaväki)
Industrie (Industry/Teollisuus)
Ideologie (Ideology/Ideologia)

X
General Note: German language has very little use for the X, especially in the beginning of a word. The word I'm suggesting is basically the only real thing-word in German starting with the letter X.
Xylophon (Xylophone/Ksylofoni)

If that's no good, Depending on how cast-in stone the script is I'd suggest the moon nazis have (during their 70 odd years stay on the moon) developed a new word starting with X.

Ä
General note, the A-umlaut is more typically used in declinations (fin: taivutus) fo words normally starting with A. There are some words starting with Ä, which fit the original nazi symbolic ethos, but I wonder how well they fit the moon:
Ähre (ear(of barley)/tähkä)
Änderung (Change/Muutos)
Ära (Era/Ajanjakso)

HTH,
Pekka