No Fancy Name,
I am a dues-paying member of the Younng Israel-Beth El of Borough Park. Please let me know if there is anything I can do for you. While money is tight, I am confident that the shul would find some appropriate way to exhibit the key and honor your grandfather.
In response to one of OP’s threads, I was one of two participants from the shul on this website. The other was Soliek. While I see him there every week, I actually don’t know if he is a member. 🙂
The Yeshiva World has set up some rules prohibiting the open exchange of email addresses. Let’s see what they are willing to do for you privately.