Excellent post Jeff. My dad was contracted to build a Lutheran church in Susanville CA in the 1960s.
And yes, he had the block mason place a cornerstone in which was deposited cash along with other items.
I've always wondered if anyone ever retrieved the items and replaced the cornerstone.
"A Cornerstone is a ceremonial masonry stone set in a prominent location on the outside of a building. There is often an inscription on the stone indicating the construction dates of the building and the names of the architect, builder or other significant individuals.
Sometimes offerings accompany the laying of the cornerstone: grain or rice, wine, and oil are placed on or under the stone to symbolize the people involved and their means of subsistence. In ancient times there was a practice of placing live humans or animals into the foundation to serve as a sacrifice to God and ensure the stability of the building.
Cornerstones often contain a cavity in which a time capsule or 'votive deposit' could be placed. Historically, local newspapers, coins in circulation, and other artifacts relevant to the time period were placed within the vessel. Today, most vessels are to be opened on a given date; traditionally, vessels were deposited with the hopes and intentions that they would never be disturbed."
Source: https://web.uvic.ca/vv/student/edges_of_time/fulltext.html
Don.....
PS: I added the emphasis