The full excavation report can be found here (now added as a Link to the site)
http://minerva.york.ac.uk/catalogue/proj_data5/PSAS_2002/pdf/vol_094/94_001_027.pdf
The following from the summary in Henshall's volume of chambered tombs.
It was excavated by Jack Scott in 1955-57.
Artefact finds include a lozenge arrowhead and two rotary querns.
Human remains - burnt and unburnt bones. Teeth from one 14-20 year old and one 25-35 year old.
Marine shells from 15 varieties of edible molluscs mostly periwinkles. 2500 from the central compartment and about the same again outside in the forecourt.
Happy to go into this in more detail if it helps.