This is a Malay private cover of Singapore 1953 (FDC) 10c Coronation stamp made by a stamp dealer like CHANG MIN YE YENG, would be a First Day Cover (FDC) featuring the 10 cent stamp issued for the Coronation of Queen Elizabeth II on June 2, 1953.
Privatev FDCs are sought after by collectors because they bear stamps cancelled on their first day of issue. 
If the cover itself was produced or commissioned by a specific stamp dealer like CHANG MIN YE YENG, it might feature a special cachet indicating its origin. 
These dealer-produced FDCs can sometimes be more desirable to collectors interested in the history of stamp collecting or specific pioneer philatelic dealer.