Hello Detlef,
I would like to wait until you receive this bolo and can show better photos of the blades tip before I would express an opinion on whether this is a tabak or not. What makes me wonder (besides poor photos of the blades tip) is the scabbard. The fact that it is pointed on the end and not cut to match the end of the blade makes me wonder if this just simply had the tip of the blade broken off at some time. All of the tabaks that I own and have seen so far that still have their original scabbards have the end cut at the same angle as the tip of the blade. Then again, it could be that your example is just different.
As for age, the workmanship of your bolo looks to be late 19th to early 20th century to me. Congratulations for another very nice find.
Best,
Robert