There are only four volumes (that I know of) in this series, and two of those are $amz(0802824439 Quinn & Wacker’s work on 1&2 Timothy). Wacker was Quinn’s student, as I understand it, and he finished the commentary after Quinn’s passing.
I finally got around to getting this set because it is now available in Logos Bible Software format, in the Eerdmans Critical Commentary (4 vols) collection.
I haven’t been exactly thrilled with Quinn’s work on Titus, though I do greatly appreciate the copious patristic references he makes in that volume. I’m hoping for similar density of references in these volumes.