I know they were doing this as reciently as 1999. My daughter, at that time a LDS (Mormon) youth, was given the names of Jewish people, and the youth
did baptisms for them in the Orlando, Florida Temple.
Remember, in LSD techings, many things continue after Death, including Marriage(s), Sex, and re-production. In order for families to be together
forever, if Covenents that were not made in this World, your surviviors will do that work in the Temple for you.
The LDS church has the largest Geneology Record system in the World. The reason is so they can do these "works" in the Temple for their Dead loved
ones (Including baptising the Dead)