Could find it in a spare parts shop/garage that deals with Peugeot parts, if one near you,
TWR........I would hunt some down, give them a call and ask ..might be lucky .
This may sound Tight of me, I priced a couple at our Local agents yesterday, just short of a tenner, I thought that a bit steep for the two, I have replaced the Original but whoever removed the Caliper the last time did not use the right T55, they had part rounded the Insert of the bolt, one Hell of a job to get out, I have just replaced the Discs / Pads on my 308 Pug.