Regarding the money that Chaim found in the suit, even though one generally acquires that which lands in one s domain, a shop is different. Since there are so many people passing through the shop, the shopkeeper does not rely on being able to acquire what lands in the area frequented by customers. The owner is assumed to have despaired of being able to retrieve his property since he can not identify it. Money is considered as not having a simmon . Although every banknote has a number, people are not in the habit of paying attention to this.
Many customers try on suits.
Potential buyers do not usually check the pockets. Neither does the shopkeeper. Whoever finds the money, can keep it. MDbusiness illustrates general Halachic guidelines, only. If you have a question, please consult a Rabbi who is well-versed in these laws.