I collect joint stamp issues (mainly FDCs and some stamps and miniature sheets) of Malaysia, Singapore and Hong Kong with the corresponding countries.
Over the last few weeks I have put up my excess joint issues covers. They are mainly covers of the corresponding country. Some are harder to find whilst others are a bit common.
If you are keen, just browse through eBay.com.my seller ID sky52200
Here is my latest listing:
You might find something interesting. By the way, if you are looking for a certain item which is not listed, just use “Ask a Question”.
If you are collecting from other countries and would like a useful source of reference, read: http://www.jointstampissues.net/index.htm
Sadly it does not write about joint covers issued by the countries concerned.