Nobody Noticed

Something very valuable was stolen and nobody noticed for a whole day. Eight cells hold two letters at once, one wanted by the across entry and one by the down. In each pair, one of the two belongs to the missing thing and the other does not. Those letters go into the shaded gap at the centre. No two of the eight cells share a row, so work down the grid: the letter taken out of the highest goes into 1, the next into 2, and so on to 8. Read the eight and you have what went missing. The eight letters left behind, in the same order, give what was left in its place. The first letters of those eight clues, in that same order again, give where the missing thing turned up two years later (8).

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
1
2
20
21
22
3
4
23
24
25
5
6
26
27
28
29
30
31
7
8
32
33
34
35
36
37
38
39
40
41
42
43
44