TexasKZ, Sirocco and Bluej58:
Thank you all for your input and references. I have downloaded the service manual (first time I ever had access to anything but the Haynes Manual).
I really appreciate each of your responses. I will read the appropriately noted sections and reply back after.
Yes, I have changed the oil filter before, several times. Not only is it a mess, requiring a big cardboard box flattened beneath it, but, one must be very careful in removing the cover not to damage the gasket. There are no replacements anymore.
I regret not buying an extra gasket in the 90's when they were still in stock at some places.