Blue Onion Reproduction?

Good morning! This blue onion cordial(?) was in a box lot from a high end estate sale. There are no visible markings. There seems to be a grey hue to glazing, and the design is not as clear as other blue onion items I have seen. The cobalt seems to have muted edges like flow blue pieces. Of course, the double lines on the base got my attention, and I wondered if this is truly a reproduction. Thanks for any input you can give. The size is 2-1/2" at top and 3-7/8" in height.

 

Blue onion (Zwiebelmuster) was made by many manufacturers. It is a popular design, just like willow pattern.

 

That looks like an egg cup to me....

 

It probably is. Would be nice to know the size.

 

I believe it is an egg cup as well.
Many years ago I found some of these in my thrift shop. Some had a Japan sticker on them. I will see if any had more markings than that and will come back if I find out more.

 

Maybe it's a reflection but it does look like there is some sort of incised mark on the bottom.