Mid 20th Omani Jambiya?

[harrywagner]

I purchased this recently thinking it was a good 20th century Omani Jambiya. I still think the sheath, handle and belt are, but I am having doubts about the blade. It looks more like a late 20th century blade to me, and I am always suspicious whenever I see the black goop used to stabilize (or sometimes attach) the blade. I would like to know what more experienced collectors think. Thanks you.

Harry