Squeaky when pedal pressed (Suitcase 88 Mk II)

[bongos]

Hi,
I've got a Suitcase 88 Mk II, and trying to find the source of the loud squeaking when pressing the sustain pedal.
I've taken the cover from the speaker/amp base (audience side), and took some photos of the mechanism near the top.

Does anyone know if there's anything pictured here that can be the cause? Otherwise it'll have the be in the piano section, and I don't really want to go there!