It's been in the family for quite a long time and after too many years I'm able to photo it and post the pictures online. Does anyone have an idea what it could be?

The spearhead is a total of 38.3 cm long. The point itself starts as a square in cross section, which after the first 5 cm gradually tranforms into a diamond(rhombus) with concave sides. The edges with the holes in them form the wider diagonal of the diamond and are around 3 mm wider than the shorter ones(which lack holes in them, but have "dimples" as if the holes were intended, but not finished.) Other such "dimples" are present and can be seen painted in white.

The point has a length of 21 cm. The hollow part of the spearpoint is 11 cm long, which means the cavity starts around 1.2 cm behind the end of the third circular decoration.

Something about the circular decorations: the second one has been cut to have a square cross section. If you have questions, I'll answer to the best of my ability.