The pit is like a drawn-out irregular hexagon 4.2m wide at the western end and 6.1m at the eastern end, where the sawtooth outcrop is a metre high and on the order of 1.0m wide. On the downhill side is a grass-covered earthen lip 3.4m wide there that disappears past the western end way up the hill.
The back wall outcrop is 1.5m high and 5.3m long, the field edge is another 1.7m back and 2m perpendicular. Between it and the 'jaggy' is the corner space where the stone heap is, the out-of-place pink stone is 0.6x0.35x0.3m. From the left of the back 'wall' to the western end of earth and a few stones is 1.5m. The larger stones at the 'wall's base are showing 0.8x0.5x0.15m and 0.9x0.4m.
On my second visit I noticed at the bottom of the pit by the 'jaggy' two small adjacent sub-rectangular rocks that are either a buried outcrop or part of walling.
On an 1882 map the only likely candidate is an unlabelled earthwork (HY43240863). This is a site I have often mused on when I have walked past the broch and the possible early wall remains. From Scapa beach if you look across to the house it is in a region of disturbed ground just below the latter [some of which appears to relate to previous (pre-1882) field boundaries]. From the coastal walk below the feature you see it sitting on a ?platform at the top of a broad U that comes down from the field fence there. You see an area of rocks above a low mound showing bare earth and small stones, with one or two isolated slabs towards the ends and several smaller ones on the hillside below. Climbing carefully over the drystane wall I snuck under the barbwire fence - I would suggest going by the metal gate at the top of the field for anyone else, you can always go down the hill then to gain a proper sense of the lie of the land on your way up. It is difficult to ascertain if the stones before you reach the earthwork are buried into the earth or evidence for rocky outcrops. Once you get there it is )like Kier Fjold) a disappointment, though if this is the place you should bear in mind it has been double-dug. There is no evidence of structure in the side of the mound you stand on, and the site does resemble a natural quarry - a flat 'wall' at the RH back above which the field fence (boundary not shown on oldmaps 1882) is seperated from by a couple of metres of earth and stone in section, a tooth-edge wall of stone to the right, and a large (relatively) shallow rectangular 'pit'. The LH end of the depression is big stones and earth. In front of the back 'wall' LH side two large slabs are partially buried, in the rest of the depression there are some smaller ones covered by the grass. In the RH corner between the two outcrops there is what appears to be a cairn of drystane wall remains, definitely not slump. Below this in the furthest part of the corner is an anomalous foot thick chunk of pink stone.
The first recorded dig at the Broch of Lingro was in July 1870. On the 11th they also began excavating a nearby mound (?HY43240863) south of Lingrow house (HY431086). This turned out to be an unrecorded chambered tomb. "The Orkney Herald" on the 26th reported that it comprised a roof of massive flags held up on pillars of undressed stones and had probably been excavated previously. The tomb was found to be full of debris, from which came burnt bones and a human tooth.