http://www.thepotteries.org/allpotters/854a.htm
I see what you mean,, I did not find which of the Ridgway Potteries used this mark but found it in several patterns by them !! The link above gives all 8 potteries that were a part of Ridgway Potteries !! Its possible that the mark was used during the organization, or when another company was added to the group !! Who knows ?? Was this set bought as one or were pieces added over time ??
As to value,, the best way to find a value is to look on ebay and see if any are selling and for what amount !! Use that as a guide !! The buying public determine`s the value !! No matter what a price guide says its only worth what someone is willing to pay !!
Could see one on the above pic OK but not the one on the right !! Last pics didn`t show !! China companies usually use several marks throughout their history !! Ocassionally you will find two different marks within the same set but the most common reason a set will have more than one mark is because they produced that pattern for a long time and just happened to update the mark sometime during that production run !!
