Hi,
I have mounted a genuine Zulu spearhead to a replacement shaft....copying one of their techniques.
Drill a smaller diameter hole (slightly smaller than the tang) into the end of the shaft (as deep as you need.... full or half 'tang' length.) If you can obtain a cow tail cut a suitable length (slightly longer than the depth of the tang) with a diameter around the same size as the shaft.....slightly smaller is much better) Remove the bone and tissue without damaging the skin. You could at this stage leave it somewhere where it would remain dry but allow access to ants ......Yes ants ... they will clean remaining residue and are excellent little 'workers'
. This can then be treated (chemicals) to remove hair (if necessary). The leather tube is then later soaked in water to soften and make the tube easier to stretch over the shaft
Heat the tang to a reddish colour and insert into the drilled hole (use leather gloves) it will burn into the wood. Remove and repeat until the tang is at the required depth. Remove spearhead. The wet leather tube is then placed/pulled over the shaft. At the same time reheat the tang and force the spearhead into the shaft. Ensure the tube is in the correct position, (often some of the tang is partly covered in leather) and then allow to dry slowly. The leather will shrink and tighten .......once fully dry trim the edges with a sharp knife/scalpel. Use a wax later to seal the wood and leather.
Hope this helps or gives you some ideas
Kind Regards David