[EE] Reverse engineering a product

Hi all,

I'm in discussion with an entity who wants a couple products reverse 
engineered. It's actually their products (and have their brand), but 
they've parted ways with their CEM/design house who now doesn't want to 
hand over the design & assembly files. And they need to be the same as 
they are currently, else it may re-trigger a re-evaluation/approval by 
one of their major clients. What they need is gerbers, BOM, and assembly 
files so they can continue to make the product.

For one product, I have a schematic, list of component part numbers (not 
calling it a BOM as there are no quantities), copper layout for all 
layers, and a sample assembled product.
For the other product, all I have is the copper layout for all layers, 
and a sample assembled product.

I'm trying to figure out what methods are available to reverse-engineer 
these products back to gerber and assembly files so they can continue to 
have it made by another CEM.
For one product I can pretty much re-design the board from the 
schematic, but not sure how to figure out the component parameters (not 
just values like 0.1uf, but also tolerances, thermal characteristics, 
etc). One is a very tight board with lots of mosfets so thermal design 
will be important.
For the other product, I can come up with a non-valued schematic (so I 
know where say capacitors and resistors would be), but won't easily know 
what the values are. Can all of these be measured?

The products may be able to be re-engineered, but I expect re-interating 
prototypes to finalize the design would be somewhat different and would 
take longer.

Any suggestions here? Are they any design houses that specialize in this?

Cheers,
-Neil.