Sweet,
I hope you do not mind that I copied your photos and lightened up the dark one (the "plug-in" photo), and then I put those photos on a quick-and-dirty web page, side-by-side.
1958-1963 261 engines oil filter options If anyone has a 58-63 261 block and can take a good photo of the "port" for the by-pass filter lines, please post a link to the photo and I add it to that web page.
If anyone has a 58-63 Canadian 261 block and can take a good photo of the oil filter "ports", please post a link to the photo and I add it to that web page.
Thanks,