Of the 17 (L) restoration chips discovered so far (
search 'resto'), two have been discovered in Argonaut Cave and two in Cyclops Depths.
edit: by comparing global and discovery timestamps, you can figure out 1 (L) dropped from merp and 10 (L) from araneatrox. The rest have been discovered by grindy folks so you'd need to pay EL to look at their globals beyond the first page.
At least three numbers (9, 15 and 16) haven't been discovered yet, which might mean these chips are not so common after all.