Yes, the links were direct links to the PDF docs themselves, they blocked those.

But you can still get to them via Lexington's website. If you go to https://lexingtonma.viewpointcloud.com/records/67918 then click on the "Files" tab, you'll see a list of documents you can download. Two of the ones I had linked to earlier are "Project Narrative" (and other links seem to open this same pdf), "Drainage Analysis and Stormwater Management Plan" has maps and 177410LT006-Certified.pdf which has very detailed drawings, maps and legends.