Mac key sector not found

Is there any step by step how properly use this?

I have WD My Book 1 TB, no password, I shucked it because the power died.

Mac recognized the drive, but can't read the data.

The chip is JMicron JMS358S on the dead PCB...

When I run reallymine decrypt /dev/disk4 a.img

_error key sector not found_

from sudo dd if=/dev/disk4 bs=512 skip=1953519648 count=1 of=kb.bin, I got this:

`00000000 57 44 76 31 e7 ca 00 00 00 68 6f 74 00 00 00 00 |WDv1.....hot....|
00000010 00 00 00 00 00 00 f0 00 00 00 00 00 00 00 00 00 |................|
00000020 01 00 00 00 00 00 46 50 00 00 00 00 00 00 00 00 |......FP........|
00000030 00 03 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000050 20 00 61 2e 00 00 00 05 00 00 00 00 57 44 76 31 | .a.........WDv1|
00000060 b5 b6 bb 04 89 03 85 2b 7e 12 58 88 17 0c fa 95 |.......+~.X.....|
00000070 fc 5e b4 28 d1 d3 66 49 ab 8d 48 8b f1 21 8f 9c |.^.(..fI..H..!..|
00000080 be 01 14 4b f0 eb 24 7f 2d 99 2e 45 80 40 23 4f |...K..$.-..E.@#O|
00000090 e0 19 03 23 18 c6 82 0e c8 f7 c8 ef 67 88 b8 13 |...#........g...|
000000a0 4e b0 15 8f d6 8e 87 03 55 fd a6 dd 4c 4f a6 ef |N.......U...LO..|
000000b0 e0 15 03 2d 56 1a bc 97 cc eb 5f a2 df c8 d7 60 |...-V....._....`|
000000c0 d7 67 89 5a cb ca d7 a5 73 f7 69 35 ce 79 fb d3 |.g.Z....s.i5.y..|
000000d0 ae 0f 80 72 cd d8 80 db d4 aa 5c db 10 08 61 84 |...r......\...a.|
000000e0 ae 14 42 54 d6 f5 54 84 b8 fd 55 23 0c 47 96 96 |..BT..T...U#.G..|
000000f0 af 84 55 2d f1 e2 d2 38 fc bb ba f4 a2 b9 c1 2c |..U-...8.......,|
00000100 c6 d3 86 90 42 3e 44 fa 5a c8 9b 10 3c e8 dc 53 |....B>D.Z...<..S|
00000110 f4 b7 10 14 b8 c0 81 be af 07 e1 1d 4e 88 a3 0a |............N...|
00000120 cd c9 b9 f6 91 6d e9 b3 10 d9 7e 86 a2 bc 41 4e |.....m....~...AN|
00000130 0e c7 27 82 23 52 e4 cf d2 88 53 55 b8 14 37 02 |..'.#R....SU..7.|
00000140 78 35 2e d4 e6 b3 f9 c9 57 7a c3 25 65 6d d0 2a |x5......Wz.%em.*|
00000150 5a 96 ca cf 64 6e cf 36 e5 48 b2 80 4d 18 f6 d5 |Z...dn.6.H..M...|
00000160 8e 3d ba 41 49 c6 74 4c a9 f3 f6 84 16 fb 4a 9b |.=.AI.tL......J.|
00000170 d8 3b b6 16 e3 e8 1c 3f 35 a5 74 fa a4 ae f4 84 |.;.....?5.t.....|
00000180 65 7c 17 13 47 64 4d 34 9c ed cf df 7e 03 f7 f2 |e|..GdM4....~...|
00000190 a4 a0 a1 eb da 78 e4 0c 2e 18 f6 6b fa fb ff 5f |.....x.....k..._|
000001a0 a0 7c 93 a8 a3 3c e8 8a 9d 14 24 a5 0b 38 fc fb |.|...<....$..8..|
000001b0 58 33 4e d8 91 f7 bb b9 ff c3 71 67 a1 59 4c cb |X3N.......qg.YL.|
000001c0 95 ff c6 d6 d5 c7 d0 b3 d2 ae 99 53 42 35 11 80 |...........SB5..|
000001d0 9a 26 70 4c 5c 7a db d0 c0 db 5b f8 0d 5c 3d d0 |.&pL\z....[..\=.|
000001e0 58 59 2d 2f 2f 79 0e 50 f9 fb a9 d8 f5 dc c2 31 |XY-//y.P.......1|
000001f0 c0 e7 cf 39 5a c6 bc 75 5b 0e 05 e1 58 f9 40 61 |...9Z..u[...X.@a|
00000200`

But I don't know what to do next with it...

Help is very much appreciated, thank you