The following case might perhaps be too localized however I'm asking it as a theoretical question in order to understand these laws in Choshen Mishpat and Evan HaEzer better.
A Kallah (bride) went to a Jewelry Store to have her finger sized and pick out a ring that the Chosson (bridegroom) would buy in order to use to be m'kadesh her (effect Kiddushin, the first stage of halachic marriage). She went and picked out a ring that was size 8 (for example). When the Chosson came to purchase the ring, the store owner made a mistake and gave him a ring that was a size smaller (7 in the example). He was m'kadesh his Kallah with this ring, which she later noticed was not the ring she had picked out because it was too small. Is there any problem with the Kiddushin since this in fact is not the ring that the Chosson had intended on buying or wanted to buy? Was there any halachic problem with the sale that would tell me that the ring in fact didn't belong to the Chosson and thus there would be a problem with the Kedushin? (See Evan HaEzer Siman 28 and 29.)