Cache is not at posted coordinates. The Adventure Lab titled Sears Kit Homes in Downers Grove is based largely in the neighborhood northwest of posted coordinates.
The final can be found at N 41 47.ABC W 088 00.DDE
The values for A, B, C, D and E will be provided in the journal entries as the Adventure Lab is completed.
NOTE: the values in the accompanying Ad Lab changed as of November 6, 2022. If you derived values from the Ad Lab BEFORE that date, you will need to revisit the journal entries.