I discovered today that there is online a thesis containing an English translation of Jerome’s Commentary on Jonah. It was made by Timothy Michael Hegedus in 1991. It’s here. I am OCR’ing the PDF as I write!
I learned about this via AWOL. There is a website Open Access Theses and Dissertations. This is a portal to other online sites of dissertations. A query on “Eusebius” quickly brought up the item.
Magic!