Ratten seat repair (Moreton CH46)

I have an old Chinese (50 Yr old) sewing box item that's made using ratten/ Reed weave used in chair seats, I want to restore it as original as possible, so I need some old worn ratten from an old chair or similar, see pics, I can buy new but I don't want to to spoil the patina, I will consider anything, try me, thanks. (PS, an old ratten straw hat may also do the job,)