After a tentative look at what should be triangle data, triangles seem to be a little odd in their metapointers:

Starting at 0x2658 (8 spaces from the right end of the second row; the pointers start just to the right of the cursor in the image. And yes, I run 32 bytes/row in my hex editor), we have the first of a string of triangles:

* Triangle 1's metapointers: 1080, 2050, 21D0

* Triangle 2's metapointers: 1150, 2270, (FFD0)

* Triangle 3's metapointers: 10D8, 2190, 2100

* Triangle 4's metapointers: 10D0, (FFD0), 20F0

* Triangle 5's metapointers: (FFE0), (FFD0), 21A0

* Triangle 6's metapointers*: (FFA0), (FF80), (FFD0)

* Triangle 7's metapointers: 1070, 2160, 2120

* Triangle 8's metapointers: 1068, (FFE0), 2130

* Triangle 9's metapointers: 10A0, (FFE0), (FFC0)

* Triangle 10's metapointers*: (FFD8), (FF80), (FF40)

* Triangle 11's metapointers: (FF38), (FE80), 2180

* Triangle 12's metapointers: 10B8, (FF40), (FF50)

First, note that triangles 6 and 10 consist

*solely* of backwards references (we've seen this before with a few quads, but it looks like it'll be more common with triangles), and that the second and third metapointers are divisible by 16 every time, while the only metapointers that are divisible by 8 but

**not** 16 are in the first slot. So: the format is (N, D, D), as compared to (D, D, N, N) for quads [where N is "normal" and D is "divide by 2"], and the pointers for triangles are

*much* later in the list than most of the pointers we've seen so far.

The "fixed" list of triangle pointers in this block:

* Triangle 1's metapointers: 1080, 1028, 10E8

* Triangle 2's metapointers: 1150, 1138, (-3)->10E8

* Triangle 3's metapointers: 10D8, 10C8, 1080

* Triangle 4's metapointers: 10D0, (-3)->10C8, 1078

* Triangle 5's metapointers: (-4)->1080, (-3)->(-3)->10C8, 10D0

* Triangle 6's metapointers: (-12)->1150, (-8)->1080, (-3)->10D0

* Triangle 7's metapointers: 1070, 10B0, 1090

* Triangle 8's metapointers: 1068, (-2)->1090, 1098

* Triangle 9's metapointers: 10A0, (-2)->1098, (-4)->(-2)->1090

* Triangle 10's metapointers*: (-5)->(-2)->1090, (-8)->1090, (-12)->(-3)->10D0

* Triangle 11's metapointers: (-25)->(-3)->10E8, (-24)->10C8, 10C0

* Triangle 12's metapointers*: 10B8, (-12)->(-2)->1090, (-13)->(-2)->1090

Note that triangles 10 and 12 seem to refer backwards such that they use the same vertex twice, so there may be something else going on here, but this is, at least, a decent preliminary list of how the triangles break down.

Consolidated list of vertices used by these triangles:

1028, 1068, 1070, 1078, 1080, 1090, 1098, 10A0, 10B0, 10B8, 10C0, 10C8, 10D0, 10D8, 10E8, 1138, 1150

Note here there are a few major runs:

* 1068-1080 (4 consecutive)

* 1090-10A0 (3 consecutive)

* 10B0-10D8 (6 consecutive)

I wouldn't be too surprised if the reason this block of triangles appears in the middle of things is because the region they're at used to be made up of quads that were broken apart (by moving one or two vertices out of the plane they were all in) prior to finishing the model.