Hi Randall,
Welcome to the forum, and thank you so much for posting a kaskara! As you have noted, there are of course distinct similarities to these broadswords of the Sudan and those of medieval Europe. Actually many 'medieval' broadswords have been created using old kaskara blades brought back from the campaigns in the Sudan over a hundred years ago, as described by Ewart Oakeshott in some of his works. Though there are occasionally European blades found in the actual examples in North Africa, most are trade blades from Germany of early 19th century to about 1870s.
I hope you can try to get more detailed photos, especially of the markings on this example. You have amazing patience having had this sword since the 1980s!!! my curiosity would have had the best of me the next day!!!
I do think that what you have is a most interesting example in that the fullering seems of more desirable type of these blades of latter 19th century form, and these markings are intriguing.
Thank you for joining us, and look forward to more pics!
Best regards,
Jim