gs -sDEVICE=pdfwrite -sOutputFile=Trolley-Trips-Through-New-England.pdf -dNOPAUSE -dSAFER Trolley-Trips-Through-New-England_ORIGINAL.pdf has solved this but file has gone from 12M to 46M for reasons unknown to me.

Thanks for the insight--if it's a timeout issue is there any way for a user (me) to know instead of filing a report like this in future? I imagine simply re-encoding anything like this not showing correctly is a good test but I hate to unnecessarily modify someone's original upload and clutter the changelogs.

Not sure related—seeing errors for https://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Trolley-Trips-Through-New-England.pdf/page21-155px-Trolley-Trips-Through-New-England.pdf.jpg and https://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Trolley-Trips-Through-New-England.pdf/page21-635px-Trolley-Trips-Through-New-England.pdf.jpg :