Here is a simple suggestion but it would need someone with the appropriate knowledge to organise it.

Almost all archives/collections consist of at least 50% readily accessible books that can be found easily in libraries. The appropriate person needs to identify all of the non-essential material that can be sold (book dealer/Ebay) and any money from that could be used to find an appropriate archive to take the more personal material that the collector has accumulated. Not ideal but at least practical.