How about a look round the southside.
In Shawlands there's an old toy factory at the closed off end of Baker St, it's only small, all the windows are out, but shouldn't be too hard to get over the wall. You can only see it in Baker Street or from the little yard at the back of Beanscene. The building Beanscene is in seems to be one of the oldest in the neighbourhood, I think it was built as a school originally.
Also in Shawlands behind the Camphil Gate tenement there are a load of old buildings which are the original front of Pollokshaws Road, mostly they made up the bakery where the bakers on baker street worked.
If you can get in to the old Elephant Cinema (above MacKays) and see if anythings left, cos it looks like the upper floors have been vacant for decades.
The Muirend cinema's going to be gutted and turned in to flats, only a recent closure, but it'll be changed forever soon. There's an old cinema building in Cathcart, it's been used as a bingo hall and is vacant at the moment, somewhere behind it there's a little hidden park.
There's a convent up of Camphill Avenue, a closed order, apparantly they wear medieval style habits and most of them follow a vow of silence, but I hear they're being moved out/have moved out. Anyone know?
Other hidden things. There's a farmhouse on Titwood Road, a coach house on Shawhill Road, an old cemetry beside Lidl in Pollokshaws, another farmhouse in Queens Park. There are iron age eathworks in Queens Park and Pollok Park, not exciting but they are there. Queens Park right at the top, Pollok Park hidden off the path near the pond in amongst the woodland.
Pollok Park has loads of decaying ornemental paths to get lost wondering up, all sorts of stuff from the estate gardens getting swallowed up. There's and open feild near the car park for the house where there are some slightly raised square and rectangular platforms which might be old foundations. Beside it there's a weir and a channel like a small version of the one to run the water wheel at the saw mill up stream.
All sorts of stuff really, that I wish I knew a bit more about or wish I could get in and have a better look at. I'm in Manchester at the moment to exploration on home turf is out of the question. There are all sorts of little left over bits, mainly from the farms and estates, before the area got really urbanised, there used to be a lot of small scale mining around there too, but there's not a lot of surface evidence except when a street caves in.
There are a lot of the old station houses, in varying stages of decay along the cathcart cirlce. Also an old signal house that's been converted in to a house in Polloksheilds if you look.
Anyway I've been rambling long enough.