Known issue with a recent batch of Meteor Cylinders. They are aware of it. I actually had a distributor send me one to play with.
They're all cast in China in the same foundry as many others. Meteor does the finishing in Italy. This includes a thickly plated band and chamber which, as Pat eluded to, can't be sanded. It can be modded on a lathe with a carbide cutter.
You shouldn't have to deal with faulty parts. If they offer you a generous refund, you could try multiple base gaskets, but the jug timing will be affected.
Hyway makes good stuff, Huztl not as good. NWP makes the best AM 026 jug I've seen all around.
Your best bet is to get a full return and a used oem jug with a new Meteor piston. Put an add here and wait for one.
You might even find one from a guy that would mod the base and band for you for better performance, and still be under the cost of your meteor jug.
@Definitive Dave