Steubenville Pottery: Do You Know It?

One of my weaknesses has always been dishes.  I don't go in for the fine china like Lennox or Mikasa.  I like the everyday stuff and particularly pieces from around 1940 or so.  And I'm rather fond of the potteries in the Ohio Valley.  Most of these are long gone but their wares are their legacy.  This is a dish from my mother's house that I've always loved:

It's a luncheon sized plate.  I've always liked the colors and the shape.  I have about 5 of these and perhaps six of a smaller, round size from the same pattern. I've looked and looked for more of them.  I know it's an old Steubenville Pottery pattern.  Here's the mark on the back:

I've searched antique malls, flea markets, yard sales, eBay, all without any luck.  I can't even find reference to the pattern name.  I've registered the picture with Replacements Limited....no luck. I made flyers with the above pictures and my contact information and handed them out at antiques malls from here to Columbus, Ohio.  No luck.   I've scoured the internet.  No luck.  I've considered that this may have been a pattern given out in boxes of detergent or some other product and perhaps that's why we always had so few.  I never remember an entire set of these being in our kitchen.  So, on my "bucket list" is a trip to Steubenville.  It isn't that far from Columbus (where son #3 attends school) but we have never seemed to take the time to make the little side trip up there.  I've spent time in other old pottery towns in the Ohio valley and I know that there are most likely people who worked their entire life in the pottery and could take one look at my picture and answer all my questions.  They may even have a few matching pieces.

So, my appeal is.....if any of you out there have ever seen this plate or other pieces that would match, please let me know.  And if anyone knows the pattern name or even a lead on information on older Steubenville products I would love to hear from you!