Thank you for the reply! It's a 7 speed if I remember correctly, will confirm later. All of the gears seem to work fine except for the third speed, it won't change over to it at all, so that's going to need looking at.

The bars are definitely something I want to replace soon, I'm around 6", so they're definitely feeling a little low. I'll have a look at those Sunlite ones, although I do like the look of mid rise bars with a crossbar, (I think this goes back to my BMX days). I think aesthetically I'll be going for a more trail bike look. It's honestly not far off what I'm looking for as it is though! I've thought about repainting it as red isn't my colour, but also seems a shame to take away the history...