Reconstruction talk:Proto-Germanic/miskijaną

Both German standard dictionaries (Pfeifer and Kluge) derive the Germanic verbs from Latin. Frings showed in his "Germania Romania" the details of the borrowing and spread of the word. And even the Deutsches Wörterbuch (which is somewhat purist and claims Germanic etymologies for words now known to be Latin) considers it "utterly improbable" (gänzlich unwahrscheinlich) that the word is inherited. And so does Online Etymology Dictionary at "mix" ("also borrowed in Old English as miscian"). Are there any reliable sources for its being inherited? (Of course, the reconstruction as such may be valid even if it's late and only West Germanic.)