He is specializing in China from what I heard.
Michael has over 30 years experience as a (the
US?) specialist dealer in Asia philately. He has had a column in Linn's Stamp News for over a quarter of a century. When he sold out to and joined with Kelleher is was a step towards semi-retirement.
Unknown if he has an equal in Australia. However, Kelleher et al does travel for shows as well as material buying and as shows return, they should hit your country. Correspondence now could set up a future visit. Of course a truly significant collection could warrant a special trip. Good luck.