I've bought far more items from Oz sellers this year than I have in the past (GSP has seen to that) and I've not had any issues so far. 

The vintage items I've found are not likely to be from asia and everyhting else I've bought has been fine as well.  I also read the feedback before making a purchase and I try to stick to sellers with a 100% rating where possible.

A couple of sellers I bought from had chinese names but it was irrelevant.  I got excellent service.  I think both of them had B&M shops as well, as I discovered when the parcels arrived.  I don't choose sellers by ethnicity, but I do read all the fine print in the listings to check that the items are in Oz, and from the feedback that the seller doesn't make a habit of advertising out of stock items.  There's some big well known Oz B&M stores that do exactly that on eBay and I won't buy from them.  You'd think they'd know better.

I've found sometimes that sellers who don't have the items in Oz often have descriptions, instructions etc in English with quite a few mistakes.  That's a red flag to me.  I was burned a couple of times in my early eBay days, so for those listings, they'd better have very high customer satisfaction, before I make a purchase.