The posted images are just very small snips of the overall scan of the purchased plans, in order to show the relative level of "blurriness" or "clarity" of the 3 different display methods of the original PDF, and PNG exported from the PDF. The middle one is the MoI Image version of the PNG.

The purchased plans allow models to be created, but the plans cannot be disseminated. They were hand drafted a few decades ago, to 1:8 scale, and one Black and White "blueprint" page measures about 25" X 36." The pdf is described as 400 dpi, and looks fairly clear. The png from the pdf, is 3,542 kbytes, and looks fairly clear also. The MoI version is still very useable, but I thought I would check on how it is displayed, as the way the curve pixels are displayed seems very "different" from the other two views.

I'll try the tracing method later today. Edit: The file is too big for autotracer.

Here is a small snip of the MoI top view of a test DXF created from the PNG by the free version of the program PDFtoDWGConverter. This display shows up very clearly in MoI, although the converted curves are not how they should be, which is no fault of MoI. (I understand that this view is of a ("vector trace"?) DXF, not a PNG).

Thank you
- Brian