I haven't needed to buy one lately so I don't know who has them.
However, the 2A .308 magazine has a flat baseplate rather than the curved of the .303, if that helps. I also think that folks advertising them as "10 round" capacity may be doing the same thing that many sellers do with 15 round US GI M1Carbine mags, calling them a smaller capacity so as to fly under the radar of EBay.