Invalid page header

I have 5 corrupted page headers as evidenced by these errors:

    ERROR:  Invalid page header in block 13947 of ...

The corruption is causing numerous queries to abort.  First option is to try
to salvage data before attempt restore from backup.  I want to try to edit
the file to zero out the bogus headers.  I realize there may be data lost
from this attempt.  I have scalpel (binary editor) in hand.

Which bytes should I edit, and what do I make them?


$ pg_filedump -if -R 1343 1343 25268878.38650946

*****************************************************************
* PostgreSQL File/Block Formatted Dump Utility - Version 1.1
*
* File: 25268878.38650946
* Options used: -if -R 1343 1343
*
* Dump created on: Wed Oct 20 19:14:06 2004
*****************************************************************

Block 1343 ******************************************************
<Header> -----
 Block Offset: 0x00a7e000         Offsets: Lower       0 (0x0000)
 Block: Size    0  Version    0            Upper       0 (0x0000)
 LSN:  logid      0 recoff 0x00000000      Special     0 (0x0000)
 Items:   -5                   Free Space:    0
 Length (including item array): 24

 Error: Invalid header information.

  0000: 00000000 00000000 00000000 00000000  ................
  0010: 00000000 00000000                    ........

<Data> ------
 Error: Item index corrupt on block. Offset: <-5>.

<Special Section> -----
 Error: Invalid special section encountered.
 Error: Special section points off page. Unable to dump contents.

*** End of Requested Range Encountered. Last Block Read: 1343 ***