There's a much better survey now published in Mining History Vol. 20 no. 3 (Barnatt & Worthington, need I say more?) along with a detailed description of the workings. It won't be available online for a few years yet, and I don't know whether there are still any copies left for sale at the Museum as we don't print as many spares these days. Having said that, we will consider doing limited-run reprints if there's enough demand, which we've just done with the latest edition.
All the unstable/delicate sections are taped off and where there is water, it's rarely more than ankle-deep. There are a few crawls if you feel so inclined but generally, you can just amble round the workings.