I am back home now and recovering.
After a lot of examination of the area and a very educational couple of hours yesterday with the local expert on the area I can confirm the following.
The engine shaft with the rising main was pumped by a waterwheel, what I incorrectly identified as the mounting for a steam engine was in fact the balance bob mounting, the structure immediately behind it is the waterheel 'pit'.
I was completely thrown initially because all the wheelpits I have seen before have what I would call 'cushioning timbers' with the through bolts passing vertically through both so as to make a 'sandwich' of the masonry. Also they are true 'pits' in that they are at least partially sunk into the ground. Apparently in the north Pennines they followed a completely different pattern.
I have no doubt about it being a wheelpit as there is a flooded trench between it and river which would be part of the outflow channel.
The shaft on the opposite bank is 'Old Engine Shaft', pumping methology a bit conjectural but I would say that this was the site of the steam engine.
The masonry lined square 'hole', I dont think that this was the shaft, there is a filled in area which is at the same horizon as the surrounding spoil and has immediately adjacent what to me is an obvious bob pit. What the 'masonry pit' is I can only guess, maybe a manway shaft, or something to do with a steam engine? More questions.
Old plans show the shaft as named above, the square pit as "Old Engine", no word "Shaft" included, make up your own minds.
Slightly further up the track going towards Dunn Fell and over on the right is a blocked up level which is Troutbeck Foot level, totally collapsed about 10 metres in. Troutbeck level higher up is similar, as is Netherhearth up on the right towards the Moorhouse bothy.
The only underground in that area is the level previously mentioned, which is not part of Metal Band but Hood Crag.
My avatar is a poor likeness.