I've got some broken valve gear on my Hornby 9F. Close examination shows that a rivet hadn't been properly hammered (if that's the term) to form a rivet head. I'm thinking it's repairable, but would like some advice.

I've also bought a replacement valve gear assembly, from Hornby. But, after fitting, it feels too tight around the pistons. Someone on this forum will know the correct fitting of replacement valve gear.

What about repairs: soldering or replacing rivets? Is it doable? How?

And then there's upgrading. Some advice for the beginner would be good.

But, my immediate problem is whether the Hornby 9F's valve gear should be 'free moving' where it enters the pistons. Two flat strips of metal, and the piston rod. The piston rod moves ok, but not sure if the other two strips are meant to move in-out where they slot into the pistons, of whether they just sit (unmoving) in those slots. ...a bit worried I'll give her some power, and end up with a mangled mess of bent metal.

Help much appreciated,

Rick