It is an old carpenter's tool box, I thought the centre round bit released the sprung catch but it doesn't!
The hinged bit with a hole in it has an over-centre hinge, so it will 'snap' into position over the pimple. Your's may need a little oil in order to achieve this.
Problem is that one is missing and I'd like to get something similar to match (or replace both)
@JurekB started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
It is an old carpenter's tool box, I thought the centre round bit released the sprung catch but it doesn't!