This is a very interesting strand and it would be nice to see a few more ATA reinactors.
Regarding buttons and badges. The ATA originally wore their insignia in silver or silvered metal. I have seen examples of the ATA buttons in white metal, and collar badges (of ATA lettering surmounted by an eagle) in hallmarked silver. I have also seen a genuine 1st pattern ATA Peaked cap badge in the standard bullion but with 'ATX' lettering ('X' being a standard abreviation for auxiliary). Unfortunately it went for several hundred at auction!
Ground staff (of which there were many) wore small brass RAF style eagles on each lapel and of course no aircrew wing or half wing. There is also reputed to be an arm badge for ground engineers.
As for buttons, aside from the above there were four sizes in black plastic. The smallest was worn on the side cap, slightly larger on the tunic pocket, larger still down the front of the tunic, and slightly larger again on the greatcoat. I have examples of the last three sizes. I guess it might be possible to make copies in resin if anyone is interested although its not something I have tried before. The ATA buttons have the lettering on a ribbed background. It was more usual to have that style than not. I have in fact contacted the original manufacturer of the ATA buttons but got no reply!
Incidentally, Nigel, if you know someone who is selling any ATA uniform I'd be interested. Can you mail me details on og.mag@NOSPAMvirgin.net?
Lastly, the IWM have released a double DVD called Ferry Pilot, with the first of two films being a wartime 20 minute or so 'life in the ATA'. Well worth getting! You could also try http://cgi.ebay.com.au/BRITAIN-AIR-TRANSPORT-AUXILIARY-TIME-FOR-COURAGE-VHS_W0QQitemZ6583828242QQcategoryZ4075QQssPageNameZWD2VQQrdZ1QQcmdZViewItem