Don't trust that museums will abide by your wishes when you donate an item.
They almost never will no matter how secure you think your agreement with
them is.
I believe that enthusiastic and competent individuals will look after
valuable items much better than most museums can.
While I have also observed this in the case of a few (former) museums in Europe, I think
that there is no perfect solution to either individuals or museums unless items are
considered national heritage and "enjoying" a different state of protection than
what is typifally seen in computer museums (In France, a very early Bull system has that
particular protection). No matter the individuals or museums, if circumstances change in
ways that were unforseen (individual dies and heritage is not taken care of as panned, or
museum shuts down and collection needs to get "disposed of" ASAP), then things
will usually not end well for the majority of a collection - again: no matter if it is a
museum or from private hands.
Cheers,
Pierre