There were some very neat Bust denomination errors that were sold in the 70's from the Bolt Collection. I have misplaced my catalog from that sale, but if I ever find it, I will send you the information... maybe you can find a copy of that catalog somewhere in the meantime.
Yes, I did read about your proposed 4th Capped Bust Half Dollar remarriage in JRJ Volume 24, Issue 1. However, based on previous JRJ die remarriage articles that I read, I thought that there was an "official process" to confirm and document proposed Bust half remarriages. For example, in Mr. Van Harvey's article (Volume 12, Issue 2) it says the following: "During a get together with several other members of the Bust Half Nut Club while viewing O122's and O123's as well as photos of the three die states of the O123, we determined that a remarriage did exist between the two varieties."..."We now have our third remarriage confirmed for the Capped Bust Half Dollar series."
However, during discussions this past week with other JRCS members, I learned that while JRCS or BHNC members may get together to informally discuss a Bust half remarriage, there is actually no "official process" for confirming and documenting a new Bust half remarriage. Each collector is left to their own opinion as to how many Bust half remarriages exist. Therefore, there is no official answer to my quiz question. Maybe this will start discussions as to whether there should be a process to officially confirm and document Bust half remarriages.