. . . . along with a dozen or so similar articles all over the web.
I strongly suspect the answer will be "No", but there's no harm in trying.
A company I have worked with in the past has a product - still in manufacture - that the design data and documentation were lost during a merger. They now wish to recreate the lost engineering data for their product and they have asked me to help.
I do not know exactly what existing data is available as of yet, (they're looking), but I strongly suspect that Gerber, silkscreen, BOM, and other data may be available as that is needed to actually manufacture the parts.
Aside from tracing the entire blasted thing by hand, is there any way to use the silkscreen and BOM files to help regenerate the schematic from the existing data? It seems like it should be doable since the Gerber gives you the wiring, the silkscreen gives you the component placement and the BOM tells you want the component is.
Aside from the data mentioned above, are there any other files or data objects I should ask them to look for?
The schematic can be a simple drawing instead of an Eagle or Fritzing file.