This is a hot topic these days
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Here's a link to an archive thread with some options, Nicks Picks just added one that would work quite well, you may need a couple washers for a touch more height though:
http://taperssection.com/index.php/topic,2499.0.htmlB&H photo has a few different options that will work, but their site seems to be down today though so I can't get you any specific links right now.
If you can get some 5/8>3/8 thread adapters there are plenty of hardware store solutions you can use from a 1" piece of pvc pipe to metal collars etc...but you do need to be able to use 3/8 bolts as the 5/8 pitch size is pretty exclusive to the audio/video industry.
Here's a pic of the set-up I use with my avantones(burgundy mics) which are the same size as the busman mics (DIN-A on those). Notice everything has/uses 3/8 hardware.(the other vertical bar is something else I made up today after refining an earlier idea, that one's DIN) Both T-bar and vertical bar where made for less than $10 combined(I've also made about 4 or 5 other bars and mounts from the same supplies).
The 2nd pic is the brass 5/8>3/8 thread adapter, metal sleeve, and 3/8 bolt w/ a couple washers to keep the bolt from topping out too early.