Blue Spongeware Mixing Bowl Robinson Ransbottom Stoneware Roseville Ohio?

1st ask I'm trying to verify these pieces.
I have heard that they are collectible, but you never know. I have to complete sets of these. Along with what looks like a tea set. Can somebody give me the information on where I would go about selling these if they are?

 

I see RRPCO items at estate auctions all the time, and the newer stuff, like above does OK but don't expect any bidding wars or prices much over $10 each.

 

I cannot find an RRPCO mark or entry in Lehner's that look anything like this one. I don't know who made these, but I'm doubtful it was them.

@Joe2007 Do you have a reference attributing this mark?

 

Can't be terribly old with the markings for dishwasher, microwave & oven proof. Guessing no earlier than the 80s.

 

True - and Lehner's copyright is 1988, so if newer than that, would explain why it's not there.

The Bowl shape in the center seems to have two lines - USA above and FP below. Can't find that either. And can't think of a reason why RRPCo would use the letters FP.

 

Friendship Pottery of Roseville, Ohio? Found this description online:

"Friendship Pottery Co. opened in Roseville, Ohio in 1973 and closed in 1996. Their pottery is attractive, durable, functional and collectible. Friendship Pottery bought Ungemach Pottery in 1984."

 

Aha!! That's it. No relation to RRPCo

 

Awesome thanks guys