You need to be the 'bad guy' and clearly distribute items with sentimental value
I tell all my probate clients this story about my mother when she handled my grandmother's estate:
"Mammaw" (my grandmother) designated in her will Mom as the personal representative for the estate. Mammaw had a simple will left all the authority to distribute her estate with my mother. That was great for Mammaw, who didn't have to put a lot of effort into drafting her will. It turned out, however, the will caused a lot of angst for Mom.
The will directed Mom to distribute all the smaller items of the estate among the various nieces, nephews and cousins. To do this, Mom allowed everyone to put a sticker on all the items to designate who wanted what. There really wasn't a problem until cousin Ken and cousin Jack put their stickers on both of my grandfather's firearms -- one an ornate pistol given to him by the town leaders, and the other the shotgun he always carried while riding the family ranch land (this was in Texas, after all).
The pistol was maybe worth $500, but it had been stored in a footlocker for 50 years. No one knew or really cared about it. The shotgun, however, had incredible sentimental value, which is why the two firearm enthusiasts in the family wanted it. Mom was faced with the unenviable situation that she was bound to upset one of her nephews in deciding who got what gun. Fortunately for her, Mom's brothers stepped in and settled the situation.
The moral here is that these kinds of things can lead to family discord if not done correctly. Thankfully, my uncles took my Mom off the hook. However, Mammaw should have been the one to distribute the items by specifically devising them in her will. Yes, that would have made some of the family angry with her, but here's why that doesn't matter: She's dead.