A question about glue

Hi everyone

I have a bachmann fairburn tank engine that has arrived with some of its already attached detailing snapped off, as well as a bag of other bits to attach. If I remember right when I was a young un my Dad made up airfix kits using polystyrene cement and I was wondering if this is the best stuff to use to attach / re attach bits.

Also I don't exactly have steady hands so what can I use to hold the peices together while they set?

Thanks in Advance
Phil