As already mentioned, the site of the short-lived Cheedale Halt looks perfect - the Halt was built for exactly that purpose of giving access to the Monsal Trail, by running a DMU service from Edale to Cheedale, via the east side of the Chinley triangle)
Finding a site in Buxton would be more of a challenge, but there are some possible locations (identified from Street View, not local knowledge)
- Where the line runs alongside Ashwood Park (about 600m from the station).
- At the point where the existing line diverges from the track bed of the old line into Buxton Midland, (about 400m from the station). The old trackbed appears largely intact on Street View, except for a very recent building at the station end (not there in 2015), and it looks possible to use that as a footpath/ cycle path to an access point either where the trackbed crosses over Charles Street (and under the line to Hindlow) or via Aldi's car park, next to the new building.
- The transfer sidings next to Hogshaw Recreation Ground (where trains from Hindlow quarry reverse to access the Cheedale line). There appears to be access to the trackside at the southern end, via Hogshaw Villas Road (800 metres from the station)
- Buxton station: would require a reversal in the transfer sidings, and the layout on the aproach would not allow complete separation of light rail from heavy rail. Even if a platform were available.
There is no direct access from the Manchester line to the Cheedale line - a double reversal in the station and the Hogshaw sidings would be necessary.
Alternatively, (or even as well) you could run in the other direction from Cheedale (as the 1987 service did). The site of Peak Forest station could be used if arrangements could be made with GBRf, whose traincrew depot it now is, but it is in the middle of nowhere (nearest operational passenger station is Dove Holes, nearly two miles away). Chapel-en-le-Frith looks more promising - the old Midland Railway "Central" station is over a mile from the extant LNWR "South" one, but the Midland line passes within 100 yards of the LNWR station and there is an access point on Loverose Lane.