[Android Q&A, Help & Troubleshooting] sigprof:
Now I don't know too… Here are the only differences in AMSS images: ot990-TNHU-2.2.2-v53R-0-amss-KY53R0M0.mbn (Hungarian OT-990) and ot990a-MVGT-2.2.2-v53N-0-amss-KY53N0I0.mbn (your dump):

--- ot990-TNHU-2.2.2-v53R-0-amss-KY53R0M0.mbn.hex	2012-04-17 00:27:46.488580578 +0400
+++ ot990a-MVGT-2.2.2-v53N-0-amss-KY53N0I0.mbn.hex	2012-04-17 00:27:46.488580578 +0400
@@ -34,11 +34,11 @@
00001050 6e 5a c5 87 08 65 96 35 12 33 97 b3 fc 54 c6 a3 |nZ...e.5.3...T..|
00001060 95 98 f5 01 83 f3 e0 db c1 e4 9b b2 6f 26 5f ce |............o&_.|
00001070 36 84 d8 1f e1 ff 05 de b9 1c be ec 08 0c a5 01 |6...............|
-00001080 68 fb 47 49 a6 6f 6f 62 5d f4 c6 45 97 12 ba 91 |h.GI.oob]..E....|
-00001090 5d 6e cd 35 83 60 6b b4 10 11 d1 cb 8d 12 67 7d |]n.5.`k.......g}|
+00001080 68 fb 47 49 a6 6f 6f 62 5d f4 c6 45 2c 5f ed 12 |h.GI.oob]..E,_..|
+00001090 25 7e 52 02 91 10 cf 8a 4a 71 c0 bb c6 ce f9 ec |%~R.....Jq......|
000010a0 bb b5 99 13 9d 4d e7 c8 0e 48 10 f9 ad c3 a2 04 |.....M...H......|
-000010b0 2d 89 b0 c4 61 1c d9 e5 54 d5 de 97 63 80 af ca |-...a...T...c...|
-000010c0 b0 9c 44 9b 1d ed 13 d0 00 00 00 00 00 00 00 00 |..D.............|
+000010b0 2d 89 b0 c4 e6 5e 83 95 91 de 40 12 f1 3b b6 9a |-....^....@..;..|
+000010c0 b9 fe 17 88 25 9e 1d 5b 00 00 00 00 00 00 00 00 |....%..[........|
000010d0 00 00 00 00 00 00 00 00 00 00 00 00 33 39 82 7f |............39..|
000010e0 b1 6a d3 b7 a2 05 15 5b 00 9d b0 a8 3f 7d fa 77 |.j.....[....?}.w|
000010f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
@@ -347234,7 +347234,7 @@
005bf6c0 07 d0 00 22 00 21 19 48 00 23 f2 f7 4c f8 28 00 |...".!.H.#..L.(.|
005bf6d0 70 bd 17 49 00 20 48 60 08 60 70 bd 50 c3 00 00 |p..I. H`.`p.P...|
005bf6e0 26 02 00 00 38 4f 4e 01 54 c3 00 00 4b 4f 4e 01 |&...8ON.T...KON.|
-005bf6f0 51 4f 4e 01 4c 4e 4e 01 4b 59 35 33 52 30 4d 30 |QON.LNN.KY53R0M0|
+005bf6f0 51 4f 4e 01 4c 4e 4e 01 4b 59 35 33 4e 30 49 30 |QON.LNN.KY53N0I0|
005bf700 00 00 00 00 8c 4e 4e 01 54 59 35 33 30 30 30 30 |.....NN.TY530000|
005bf710 00 00 00 00 5b 4f 4e 01 53 c3 00 00 57 4f 4e 01 |....[ON.S...WON.|
005bf720 48 4e 4e 01 50 00 00 02 40 11 8f 01 c0 fd 89 00 |HNN.P...@.......|
@@ -649949,7 +649949,7 @@
00a60970 02 02 00 00 04 00 00 00 4d fc 20 01 b9 1a 76 00 |........M. ...v.|
00a60980 01 00 00 00 0a 02 00 00 04 00 00 00 0d fc 20 01 |.............. .|
00a60990 b9 1a 76 00 01 00 00 00 07 00 00 00 08 04 00 00 |..v.............|
-00a609a0 31 38 3a 30 33 3a 35 33 00 00 00 00 53 4e 44 00 |18:03:53....SND.|
+00a609a0 31 31 3a 33 34 3a 32 37 00 00 00 00 53 4e 44 00 |11:34:27....SND.|
00a609b0 00 00 00 00 00 00 00 00 03 00 00 00 e9 00 00 00 |................|
00a609c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
@@ -954750,7 +954750,7 @@
00fb9c50 2b 9c 7b 46 2a 02 19 00 08 00 00 00 52 eb 22 7f |+.{F*.......R.".|
00fb9c60 5d 02 19 00 08 00 00 00 ce 32 ef 15 80 00 19 00 |]........2......|
00fb9c70 08 00 00 00 b3 6b 31 ea 8d 00 19 00 08 00 00 00 |.....k1.........|
-00fb9c80 ac b9 0e 00 4e 6f 76 20 31 35 20 32 30 31 31 00 |....Nov 15 2011.|
+00fb9c80 ac b9 0e 00 4f 63 74 20 31 38 20 32 30 31 31 00 |....Oct 18 2011.|
00fb9c90 4d 37 36 58 58 2d 54 53 4e 43 4a 4f 4c 59 4d 2d |M76XX-TSNCJOLYM-|
00fb9ca0 36 30 35 30 31 30 30 35 00 00 00 00 c1 0f 00 00 |60501005........|
00fb9cb0 3b 01 00 00 08 00 00 00 3b d9 f5 00 63 d9 f5 00 |;.......;...c...|
@@ -993528,14 +993528,14 @@
010bfc90 00 00 00 00 00 00 00 00 00 00 00 00 1b 07 99 c0 |................|
010bfca0 24 46 2d a8 00 00 00 00 00 00 00 00 00 00 00 00 |$F-.............|
010bfcb0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
-010bfcc0 00 00 00 00 50 59 35 33 52 30 4d 30 00 00 51 59 |....PY53R0M0..QY|
-010bfcd0 35 33 52 30 4d 30 00 00 48 59 35 33 52 30 4d 30 |53R0M0..HY53R0M0|
-010bfce0 00 00 45 59 35 33 52 30 4d 30 00 00 45 59 35 33 |..EY53R0M0..EY53|
-010bfcf0 52 48 4d 30 00 00 4b 59 35 33 52 30 4d 30 00 00 |RHM0..KY53R0M0..|
-010bfd00 4b 59 35 33 52 48 4d 30 00 00 4c 59 35 33 52 30 |KY53RHM0..LY53R0|
-010bfd10 4d 30 00 00 4c 59 35 33 52 48 4d 30 00 00 53 59 |M0..LY53RHM0..SY|
-010bfd20 35 33 52 30 4d 30 00 00 54 44 45 46 41 55 4c 54 |53R0M0..TDEFAULT|
-010bfd30 00 00 43 59 35 33 5a 5a 4d 30 00 00 58 44 45 46 |..CY53ZZM0..XDEF|
+010bfcc0 00 00 00 00 50 59 35 33 4e 30 49 30 00 00 51 59 |....PY53N0I0..QY|
+010bfcd0 35 33 4e 30 49 30 00 00 48 59 35 33 4e 30 49 30 |53N0I0..HY53N0I0|
+010bfce0 00 00 45 59 35 33 4e 30 49 30 00 00 45 59 35 33 |..EY53N0I0..EY53|
+010bfcf0 4e 48 49 30 00 00 4b 59 35 33 4e 30 49 30 00 00 |NHI0..KY53N0I0..|
+010bfd00 4b 59 35 33 4e 48 49 30 00 00 4c 59 35 33 4e 30 |KY53NHI0..LY53N0|
+010bfd10 49 30 00 00 4c 59 35 33 4e 48 49 30 00 00 53 59 |I0..LY53NHI0..SY|
+010bfd20 35 33 4e 30 49 30 00 00 54 44 45 46 41 55 4c 54 |53N0I0..TDEFAULT|
+010bfd30 00 00 43 59 35 33 5a 5a 49 30 00 00 58 44 45 46 |..CY53ZZI0..XDEF|
010bfd40 41 55 4c 54 00 00 00 00 00 00 00 00 00 00 00 00 |AULT............|
010bfd50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*

The first block looks like some checksums, and the rest of differences are just build timestamps and version numbers. I'll look at the Android side later.

BTW, the differences between ot990-TNHU-2.2.2-v53H-0-amss-KY53H0C0.mbn and ot990-TNHU-2.2.2-v53R-0-amss-KY53R0M0.mbn are just as big as these :) Apparently Alcatel did not find anything to fix in AMSS between those releases — either their baseband code is perfect, or they don't care about it, guess yourself which is true.