Rebuilding DB from broken hardrive.

I was trying postgres for about a year and the hard drive died.
Using some block copy and other tools I was able to retrieve some data
however it's missing directory names. 

Eventually, I was able to connect to my db. However, when I make a
query. It comes back with following messages.

WARNING: 4 attrdef record(s) missing 
ERROR: could not open relation 1663/17230/17235: No such file.

When I'm looking at my lost+found folder and
recreating /var/lib/data/global and /var/lib/data/base/1.

It would be nice to know how each directories are related to each other
or at least a pointer to where I should look.

Thanks,