I was riding my 6-speed Brompton late last night when I heard this weird noise coming from my bike. The 2 speed derailleur detached from the frame and was hitting the spokes of my rear wheel.

I need to replace the cable spring that fits onto the chain pusher arm (leg?) and the bolt that screws into the chain pusher assembly. Can I get them at my local hardware store or bike shop or are they special order items only available at Brompton?