Was that called Dewsnap sidings?
No, there were four distinct sets of sidings at Guide Bridge:
1)Brookside , the largest situated between the Stalybridge line and the Ashton Canal, now used by Freightliner and track maintenence plant.
2) Avenue sidings between Stalybridge line and River Tame, used for storing Freightliner rolling stock
3) Liverpool sidings to the south east of the Glossop line, used for many years for loco stabling, all track now lifted.
4) Cock Lane sidings accessed from the Stockport line beyond Stockport Junction, these were LNW later LMS operated, not GC and not electrified. Houses built on that site now.
Dewsnap yard was probably bigger in terms of capacity than all the above combined, had its own large signalbox which did not control traffic on the main lines. Industrial units now occupy the site.
Across the main line from Dewsnap was situated the vast Dukinfield wagon works of the GCR, the buildings mostly survive in multiple use.