After reading your post, Alan, I laughed at myself awhile. I admitted to myself for the umpteenth time that - verily - there does not exist a substitute for experience. Oh well, at least I did not do irreversible damage to the scabbard. When my dear wife's jobs are done, I can go the shellac way. (Searching for a Danish oil product was totally fruitless.)
This has been a wonderful experience for me, making the scabbard, and during all this time on this thread I have been the recipient of all your kindness, helpfulness and knowledgeable hints & advice. I thank you!
To end off the thread with a few philosophical words from me, I can say this home-made scabbard, however aesthetically imperfect as you all agree, does add character to my Bugis Riau keris. You will agree that if a person who truly knows kerisses looks at it for the first time, he is sure to remark that this scabbard, although a recent non-Indonesian replacement, was made specifically for this keris. I have a feeling that not very many antique kerisses in collections still have scabbards that they can call their very own.