Perhaps a speaker of a continental Germanic tongue could chime in?
As a native Russian speaker, but one who moved to the United States 20 years ago, I do find the Google translation of Russian to be really excellent, as well as vice-versa (but Russian is much more widely spoken, including of course, by a Google Executive, than Frisian.)
A lot of the words coined in the essay are Anglicized versions of words used in other Germanic languages. Sourstuff as oxygen, for example, is consistent with the word in several other languages (Sauerstoff in German). Certain words, like uncleftish, are based off of the root words in the original Greek or Latin (the German word is just Atom). I could attempt to translate the essay into German, but my German is quite bad and would no doubt have some serious grammatical errors :P
As a native Russian speaker, but one who moved to the United States 20 years ago, I do find the Google translation of Russian to be really excellent, as well as vice-versa (but Russian is much more widely spoken, including of course, by a Google Executive, than Frisian.)