An excellent article was recently published in the Journal of the Philatelic Society of Kuching Sarawak on 19 December 2019 Volume 11 No 2 by Dr Indraneil Das, Iu Cho Seng, Nedumaran Lingappan and Genevieve V. A. Gee on the 600th Anniversary Malaysia – China Relationship stamp issue.
This issue is shrouded in mystery.
It was originally supposed to be released on 07 July 2005 but was postponed to 21 July 2005. The issue had Presentation Pack, a stamp and a Miniature Sheet which were replaced.
The article explored various information on the issue. Have a read.
More such snippets can be found at: https://myfdc.me/errors-and-unissued/