We are Gabaim of a Shul and have the following predicament: An individual donated an expensive Paroches to our Shul three years ago Leiluiy Nishmas for his father A”H, and now another shul member has donated a Paroches which is more expensive and nicer than the original one and we would like to switch it? However, the original donor of the current Paroches is very upset with our decision and says we don’t have the right to switch it. What are we to do?
He does have a claim and therefore you should not switch it foever, but rather switch off, such as to switch the Paroches every other month, and hence each donor will have his Paroches up for some time during the year. However, he does not have a right to claim permanency of the Paroches, that his remain up the entire year. Likewise, if his Paroches is no longer in good condition, then you may switch it permanently and the above only applies if it is still befitting for its use.
Explanation: When a person donates an item to a Shul, it becomes the property of the community and the community maintain certain rights of usage over it, and it is in their discretion to use it or not, and to decide on its frequency of use. Thus for example they can choose to sell it to another Shul, or sell it and use the money for a higher purpose even if Lo Nishtakah Hashem Mimenu [that the name of the donor is still apparent upon the donated item]. Thus, it is clear that the donor is not considered to have acquired the rights for his item to be the one used in the Shul, if the congregation desires otherwise. Nonetheless, just as we find regarding a Sefer Torah that the Poskim rule that when a second Torah scroll is donated that one should take turns reading from the two donated scrolls, so too, this applies likewise with other items that are donated to a Shul by two different people, that they should take turns using them.
Sources: See Michaber O.C. 153:14; Y.D. 259:3; Biur Hagr”a 153:38; Chochmas Adam 148:16; M”B 153:100; Maharam Shick C.M. 18; Yabia Omer 7:23; Shevet Halevi 1:205; Minchas Yitzchak 2:76-4; Igros Moshe 3:26; Mishnas Yosef 4:26; Piskeiy Teshuvos 153:23 and 31