Missouri Still Birth and Miscellaneous Records.
This database contains various miscellaneous records from Missouri from 1805-2002. These records were mixed in with birth, marriage, and death records located on microfilm from the Missouri State Archives. Examples of types of miscellaneous records presented here include: still birth records, school censuses, board of education minute books, receipts, and probate records.It's organized only by county name, and unindexed, so when I feel bored I can browse through the 72,000 pages for St. Louis. (not likely)
Missouri Death Records (1834-1931)
These records come from the Missouri State Archives, but there are some pre-1910 records here that aren't at the state's Missouri Digital Heritage site. I suspect everything from 1910-1931 in this database can be found in the state's death certificate database.
Missouri Marriage Records 1805-2002
I was all prepared to discover that like the Missouri Birth Records they uploaded a few weeks ago, there were less than a dozen entries in the last thirty years or so of this database. But I was wrongly prepared. This is a conglomeration of marriage license applications, marriage licenses, and marriage indexes.
While some counties have the actual licenses, with the date the marriage was solemnized, it seems St. Louis has only the applications, through 1959. The Ancestry index lists the application date as the date of marriage, which of course is wrong. There's no evidence the marriage happened, just that it was planned, and it almost certainly happened on a different date.
After 1959 some marriages are indexed, but the only information you get is names, date, and the book and volume number, or certificate number. Of course, this could be more than you already knew, and you can use this information to order the certificate from the county clerk. I don't know what fraction of the marriage indexes they have scanned, but it's certainly not complete, for example there were only 24 marriages indexed for all of 1960 in St. Louis.
I did find the applications for several family marriages, and one or two licenses for family members who were living in neighboring counties. Only one surprise. There is a marriage license (without a date of marriage) for a distant Cruvand cousin who prior research indicated never married. Of course, he might not have. This application also happens to have a parental consent signature for a minor female. So there could be a story there.