Your description is very clear and has I think moved me a step closer to the solution. Pulling the pedal up and forward, there is no snapping into position. Instead the pedal barely engages with the bar - not nearly enough to push it down - and then slips off the bar. I see that the pedal rotates on a chrome pin, but there are also two holes forward of this that seem to be missing something, possibly a second pin or fitting? Difficult to describe - does anyone have a link to a photo of what this should look like?