After a bunch of back and forth, it appears that the reason Chase would provide a medallion signature guarantee for my brother, and not me, is that he's an executor of my mother's estate. (Mark and I both have accounts at Chase, which is part of what confused me.)
The banker at Chase suggested talking (again) to either Vanguard or TIAA and see if they will do this. She said she looked online and it said TIAA does provide these, and I've had an account with them for at least 30 years.
Also, Attitude's and my joint account at Chase is dormant, and to wake it up, one of us needs to go to a branch, talk to someone, say we want to take the account out of dormancy, and make at least a $1 deposit or withdrawal. And no, I can't pick up a deposit slip, take it to a teller, and make the trivial transaction, we would need to actually talk to someone. To keep it active, we will need to poke at it at least every 364 days. But doing this once would at least reset the clock of "inactive account, transfer funds to the state for safekeeping."
The banker at Chase suggested talking (again) to either Vanguard or TIAA and see if they will do this. She said she looked online and it said TIAA does provide these, and I've had an account with them for at least 30 years.
Also, Attitude's and my joint account at Chase is dormant, and to wake it up, one of us needs to go to a branch, talk to someone, say we want to take the account out of dormancy, and make at least a $1 deposit or withdrawal. And no, I can't pick up a deposit slip, take it to a teller, and make the trivial transaction, we would need to actually talk to someone. To keep it active, we will need to poke at it at least every 364 days. But doing this once would at least reset the clock of "inactive account, transfer funds to the state for safekeeping."