In the May 2011 issue of Indo-China Philatelist (ICP #198), philatelist Thierry Wiart called for attention of a Cambodian bogus issue featuring Charles de Gaulle.
There are at least two more bogus stamps not mentioned by Wiart, they are in the same presentation but depicting helicopters, and the country name is now in English but not French. Below shows the stamps in horizontal pair:
The selvedge suggests that they may be in bottom left corner position of a sheetlet, it is unclear if a 9v sheetlet exists, just like that of de Gaulle.
The de Gaulle series has used the country names of Cambodia, Laos and Vietnam. So far only Cambodia has the helicopters but not the other two Indochinese countries.