Plastic part for buddy seat---69 Charger

[Chatt69chgr]

I have attached a picture of a buddy seat.  There is a plastic piece that goes from each hinge around the back of the upper part of the seat that folds up and down.  I think it hides a slit in the cover.  I need a black one.  Mine interior was dark green and the green dye appears to make the plastic fall apart after many years.  As a consequence, mine is brittle and turning to dust.  Black plastic seems to hold up OK. 

Does anyone know where I could buy this piece?  I've looked at Legendary, RT Specialties, and Mega Parts USA.  No luck.

I supppose you could fabricate this out of a piece of stainless steel and paint it.