For reader’s convenience, the bottom of each page indicates the portion of the biblical text covered in that page’s facsimile, with hand-written notes over the facsimiles to indicate the starts of chapters.
The quality of the scan seems to be quite good. Below is an excerpt from Deut 30:2 (on pg. 248) showing the asterisks and metobelus used to mark what seems to be a revision toward the text represented in the MT.
Each of the files is reasonably large (75.7–81.5 MB). So, they may take some time to load on slower connections or browsers.
As a side note, these PDFs cover the whole New Testament. But, the SBL Handbook of Style notes a 6-volume edition of Strack and Billerbeck’s work (§6.4.7). Does anyone with better knowledge of the 6-volume version know whether (a) volumes 4–6 have contents beyond those of volumes 1–3 listed above, (b) the 6-volume version is simply a different printing of the 3-volume version, or (c) something else?
As a follow up to noting Rob Bradshaw’s additions of Charles Simeon and John Lightfoot’s works in conveniently accessible PDF files, some other possibly helpful resources across which I’ve recently stumbled (sometimes apparently afresh) include:
Internet Archive has the three main volumes of Edward Robinson’s Biblical Researches in Palestine (Boston: Crocker and Brewster). The volumes record observations from Robinson’s mid-19th century travels in Palestine with Eli Smith and others. On Internet Archive, the volumes are included on the same page with several others, and the labeling is somewhat unclear. The direct links for the Biblical Researches files are, however, as follows: vol. 1, vol. 2, and vol. 3.