On 15/03/2012, at 9:21 AM, Greg Kogut wrote:

I'd like to know precisely which kernel recipe/config to start with.

I don't know about finding which recipe it was built from, but you may be able to get the config. On the running system, run 
gunzip -c /proc/config.gz | less

Note that this will only work if the kernel was built with IKCONFIG_PROC enabled. 

Hope that helps,