Thanks Deejay,
I'm taking the whole mower in to get the blades done properly. I'll leave the front roller for the moment, I've flipped the shaft prior to replacing, which hopefully will be a little better. The end caps are alloy, not plastic. The grub screws (if that's what they are) have round holes in them, so I'm unsure how to remove them. I may get my f.i.l to machine up a nice stainless shaft (he's got plenty lying around) and make up some bushes to use with the current end caps to firm things up.
