If you need them sooner, Alex (CAHEK) has some he could sell you, but they're not Java. Depending on how desperate you are, you could fit the grey seats now, wait till some tan ones come up for sale, then sell off the grey ones on eBay.
If you click on the eBay search link above then 'Save this search', eBay will e-mail you as soon as 3rd row seats come up for sale.
I used this feature to find mine. In the 6 months I was observing the eBay market (August 2006 to January '07) at least 6 pairs were sold. (3 grey, 2 tan/java, 1 black/anthracite.)
There was a brand new pair of anthracite seats that have been offered several times but didn't sell as they were overpriced. A black pair did sell in October for US$1425, but that was seats only - no seatbelts or brackets. Black seats tend to attract higher prices at auction as they are less common.
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