We have a small collection of items, (scarf, shirt, umbrella, a bag of tissues, etc. [nothing of nearly significant value]) that have been left by us over the years. Can we assume that the owner has given up on finding them and therefore use, donate or discard them or must we hold on to them?
The halacha is that if it came into your jurisdiction before the owner knew that the item was lost, and gave up on it, then you are considered a “shomer” on the object and it has to be watched indefinitely. The poskim however say that items that aren’t “irreplaceable” to the owner, that the finder may appraise the items value, (if it is a used item, what its present value is) and write it down, together with any other pertinent information, such as when, and where it was found, any accompanying simanim, etc. Then he just has to keep the record of what he found.
If the item is an irreplaceable one, (an old heirloom, or teffilin) then it has to be kept.
If the item doesn’t have a set value, he should ask 3 people familiar with this type of object.
CH:M 262-3, R’ Moshe Feinstein zt”l, quoted in Kuntres Mitzvas Hashovas Aveida, and Igros Moshe CH”M 2-45, Halachos of other people’s money pg 188 from R’ Eliyashiv zt”l, Mishpat ha’aveida, siman 267, ftnt 286, brought in Hashavas Aveida K’hilchoso, chap. 6 ftnt 14.