Went back down to the club this afternoon - removed both self-bailers and used silicon sealant on the glands. The starboard one [the one that was leaking] seemed to seal easily and hopefully will be watertight. The port self-bailer was a bit of a mess sealing, so I hope it does now seal properly and that the leak has not been moved from starboard to port sides!
Anyway, as it sets I hope this will seal both self-bailers and we get a more watertight boat. In the process the starboard rear seat support came off, so that will have to be mended before sailing again.
Daniel moused the shackle on the genoa, as that came apart when we brought the boat up the slipway yesterday. I think all the shackles are now moused.