There should be 40 cells in a 10S4P configuration. They'll be 3.7v (4.2v max) and 2200maH capacity each to give 37v 8.8aH total. The deignation on them doesn't look like Sony, Panasonic or Samsung, so probably Chinese copies.
FWIW, Sanyo/Panasonic moved production of 18650 cells to China last summer, so my guess is that even their cells will have been widely copied by now. These are up to around 3 to 3.1Ah, rather than the 2 to 2.4Ah or so typical of the older generation laptop 18650s.
Even the Sanyo/Panasonic cells aren't great though, with a pretty high IR, so it's anyone's guess what the copies might be like. Sony Konions are probably amongst the better cells, but don't seem to be used in laptops much, so don't seem readily available (except as old cordless tool pack cells).
If I was rebuilding one of these packs then I'd not bother with the cheaper low discharge rate laptop 18650s, but would try and get hold of some cells from either the Makita or DeWalt cordless tool packs. They are massively better in terms of internal resistance and hence efficiency, and if you can find a source of old Makita BL1830 packs you will probably get a lot of very good cells, as these have an internal fault that causes the end cells in the pack to prematurely fail, leaving most of the other cells in good condition.
