how do you preserve an aggregate of family memorabilia...

[JimDandy]

2. Hoarders don't want to give up the items,

but genealogical hoarders hoard family items because they want to preserve them. They often verbalize that they are the person in the family who will best be able to care for the items. It's hard for them to even temporarily allow others to take items elsewhere to be photocopied or photographed. In addition they usually have dreams of organizing, documenting and publishing the material in some manner, but can become overwhelmed quickly by the sheer volume of their collection and give up on those activities... but they keep collecting more as each person in the family dies.

It sounds like your hoarder is elderly, so they may not be as tech saavy as you. One proven way to start getting the info to other family members has been to offer to photograph/scan/copy the hoarder's material and enter it into a database at the hoarder's home. If they have any remnants of their organizing/publishing dreams left, suggest that your doing that would help them in their efforts.