I couldn't find a copy of this document. However on my hdd I have these documents:

Maemo_5_Desktop_Widget_UI_Guidelines_v1_1_en.pdf
Hildon_2_2_Widget_UI_Specification_v1_0_en.pdf
Maemo_Diablo_Reference_Manual_for_maemo_4.1.pdf
N900 (RX-51) SM L1&L2 v1.0.pdf
N900_RX51_schematics_v2_0.pdf

Here are the removed sides/documents as link to the nokia developer page.

Maybe we can collect every document. In total there were 5 documents.