Excellent that we have a voice in TfGM, please keep us updated, Steve! A line to Stockport would be fantastic.
I lived in South Reddish for 5 years before moving here and from my experience of constant heavy traffic on the only other commuter routes to Manchester (both road of course) the place was crying out for a regular rail service to Manchester taking in both Denton and Gorton. If the will was there it would be up and running now.
The example is not quite the same as Marple as we already have two stations, but given that both serve Piccadilly and neither Stockport, it has always seemed stupid.
The Middlewood Way is a popular location but if the railway was resurrected tomorrow with a curve off to Hazel Grove I would not be sorry. Extension to Macclesfield would be useful too though think they have trammelled over it like all the other hacked Beeching lines.
I read somewhere that a service to Stockport could be diverted at Belle Vue, and given all the waste land around there this does seem a viable option.
And historically one shouldn't rush to blame the Conservatives for all the problems of the railways. Ernest Marples was a crook, and privatisation was a grave mistake, but Labour continued presiding over (after promising to reverse) a huge amount of Beeching cuts from 1964 right through to 1970 and beyond. They even closed lines down that he hadn't even recommended which would be an absolute godsend in easing motor congestion were they open now. The whole debacle is under-reported and often misunderstood.