You can have a look in Deep Level (no SRT), Hospital Level (there are a few shafts to cross to get in deeper, so a SRT harness and cowtails are needed for the safety lines).
There are a a few short surface crosscuts that give access to very deep shafts.
Also some short old workings, such as Cobblers and I think Gods Blessing, which is right up the fell.
Best bet would be to get hold of Eric Hollands book "Coniston Copper Mines: A Field Guide", pronto by the end of the week!
Mr Mike www.mineexplorer.org.uk