I am sure I am a bit late in noticing this, but Rev. James Swetnam, S.J., Professor Emeritus of the Pontifical Biblical Institute, and one of the leading scholars on the Epistle to the Hebrews, having studied it for over 50 years, has produced an online commentary on the epistle over at his website, James Swetnam's Close Readings. At a bit over 200 pages, he spends most of his time on the text proper, providing an invaluable resource for students of the enigmatic epistle.
By my rough count, Swetnam has produced 37 articles on Hebrews alone, to go along with hundreds of other publications. His dissertation, Jesus and Isaac: A Study of the Epistle to the Hebrews
in the Light of the Aqedah (Analecta Biblica, 94; Rome, Biblical Institute Press, 1981), was written under the supervision of Morna Hooker. Enjoy the rare treat of a free publication from a master scholar.