Just in case you didn't receive or notice my reply to your earlier request for info on the Tuscania, I'll repeat it here. The list of Tuscania losses includes 91 names and their company designations.
--------- I just ran across a downloadable 1920 unit history of the 20th Engineers that includes a first-hand account of the sinking. It's in the book's section on the Sixth Battalion, which apparently was aboard. There's also a list of casualties at the end of the book.
You may already have this, but if not here's a link to the book: