Two Matching Pottery Urns - Anyone Recognize?

Hello folks! I've got these two little urns that I've had for years but I've never been able to find out anything about them. The taller one is 4 3/4" high and 4 1/8" across; the smaller one is 3 3/8" tall and 3 3/4" across. I think they might be Continental as the /6 and /4 don't match any decimal measurements for these two vases. Any help as to manufacturer, country, age, etc. would be much appreciated. Thanks!
Don

 

RRPCO (I think) did a number system like that.

 

They scream German salt glaze to me. Numbers look German too.

 

I thought that too. Now that I think about it...RRP I think had a number and a / and that was it. I tried

 

Thank you, kraftblue - my first thought was also RRP but it is not really their style and the clay is just too white. Ownedbybear has come to my rescue again. German salt glaze makes a lot of sense. I don't know why I didn't think of it. The gray rings have a pebbly texture to them. And the craftsmanship is exceptional - bottom nicely ground, no bubbles, no drips. Really very nice pieces. Thank you both for your efforts.
Don

 

Have a look on the fatlava website. They've a lot on numbering styles.