I am late to this thread but as a philologist, historical linguist and German-speaker, I read the @abgemacht bits with amusement. That term actually made it directly into English as a cognate, which has wonderfully ambiguous usage ... especially with respect to Diplomacy. The English word is "made up", which has two primary meanings:
"Reconciled" (or "agreed") as in "Redhouse made up with his girlfriend after suggesting on an internet forum that he might ask somebody else to marry him."
or
"Invented" as in "Abge made up an alliance with Germany in order to convince England to vacate STP".
So be careful.
[grammar]
And now that I am started, consider how little "up-ness" is involved in "to make up". That is precisely because it comes from the German "ab-machen", with "up" being the English variant of "ab" (which has nothing to do with "up", but rather means from, away from, or ... in the case of mountain climbing, for instance, _down_ from).
This also explains why "up" is not a preposition here, but part of the verb. (If it were a preposition, what is it's object?) And how would you reword a sentence such as "I made it up" in order to avoid ending it with a "preposition"? "It is a thing up which I made." ?? Any better ideas? Even more convoluted than the oft-quoted "Ending a sentence with a preposition is something up with which I will not put."
[/grammar]
Carry on.