There are loops and wires at the back of the hairpin. They are not only the structure for the hairpin layers but also how the beading is set on the hairpin. In addition, there are threads in different colour as well - the evidence that shows the hairpin owner(s) had done many repairs.
To repair the beading, the beads should be removed from the hairpin and cleaning is certainly needed.
The loops are still there but some wires are broken or detached from the hairpin. There are wires that wrapped with thread and I have no idea about the reason for doing this.... maybe it is because the wires are so thin and the colour is the same as the hairpin layers, so it would make the repair much easier if there are two colours. There are also broken hoops that connecting to the loops and could be from earlier repairs.
All the threads and wires are removed and the beading is detached. Ready for cleaning. I did it with sodium bicarbonate.
They are in proper colours now!