Your bridge IC appears to be a JMicron JMS538S which confirms that your bridge PCB does indeed handle the encryption.
When connected on its own, the PCB identifies as a WD My Book 1140. This means that the "ROM" must be valid.
Code:
idVendor: 0x1058 = Western Digital Technologies, Inc.
idProduct: 0x1140
bcdDevice: 0x1016
iManufacturer: 0x01
English (United States) "Western Digital"
iProduct: 0x02
English (United States) "My Book 1140"
iSerialNumber: 0x05
English (United States) "5743415A4148353037363230"
However, when the PCB is attached to your HDD, the USB mass storage device identifies as a JMicron USB to ATA/ATAPI Bridge. Therefore ISTM that there is a problem in the Smartware area at the end of the drive's user area.
Code:
idVendor: 0x152D = JMicron Technology Corp.
idProduct: 0x0539
bcdDevice: 0x0100
iManufacturer: 0x01
English (United States) "JMicron"
iProduct: 0x02
English (United States) "USB to ATA/ATAPI Bridge"
iSerialNumber: 0x05
English (United States) "57442D5743415A4148353037363230"
IIUC, your key sector would suggest that the Smartware area begins at sector 0xE8DF8800, ie LBA 3906963456.
Code:
Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00000000 57 44 76 31 89 D4 00 00 00 88 DF E8 00 00 00 00 WDv1‰Ô...ˆßè....
^^^^^^^^^^^
ISTM that your best DIY approach would be reallymine. Perhaps cloning the drive with ddrescue or HDDSuperClone would be advisable. You might also consider applying the mod_02 patch with HDDSuperTool just in case the drive has a "slow responding" problem.
Ok Let me check and get back to you.