Well the line north from Shaw to Milnrow was single tracked I suppose in the late 1970s. I remember it being double when I was little. Having recently (7th May in fact) driven off the M62 junction 21 following the signs which say 'Huddersfield A640' just as you go back under the M62 on the left the track is now re-doubled. So that's something concrete that's happened (or metal I suppose). Therefore it has definitely been relaid. No sign of overhead wires though.
If you're driving that way if you turn back towards Milnrow there's a pub called the John Milne. If you go into the beer garden at the back, jump over the fence there's an old bridge over the railway line which is only passable on foot (or horse I suppose). Perfectly possible to stand on it and watch whatever rolling stock might flow underneath with no danger from passing traffic (as there isn't any). Unless they have decided to knock the bridge down to make putting the overhead wires underneath easier. You don't actually need to go via the pub but it might be easier to park in the pub car park if you do.
Here's where I mean. The bridge is covered in grass by the way. Just getting the hang of this linking thing.
Here's a Streetview view of it. The latter view shows in fact you can just walk over the bridge from the pub car park without having to go over any fence. Maybe it's a public footpath.