Here are some ways to use recent Treasure Hunter Adventures supplements and scenarios in the world of Indiana Jones.
Generic Heroes
These print-and-play characters work just as well in the 1930s as they do in the modern day, with the possible exception of the Technician. Even so, if that character functions more as a mechanic, then it can work, too.
The Shrine of the Sybil
The notion of exploring tunnels and caverns beneath Rome takes on added drama if there are Nazis present in the city, as during the build-up to World War II, or if the Allies are bombing it. The heroes could be racing to finish this adventure as the bombs are falling!
Past, Present and Future
The events of this scenario are affected in the same way as The Shrine of the Sybil, above.
The Reckoning
The finale for the Apotheosis Campaign ties up any loose ends from previous adventures, and so it is limited only by what has happened during previous scenarios.
Apotheosis Campaign Guide
Limitations do not apply to this supplement, which just provides guidance for running the scenarios in the campaign.
Curses!
This shot supplement is not affected by time period.
OSS Report on the Invisible College
The OSS came into existence at the start of World War II, meaning that it wasn't around during the time period of the first three films. In Kingdom of the Crystal Skull, however, it is revealed that Indy and Mac worked for the OSS, and they would have been active during the period depicted early in Dial of Destiny. In fact, Basil Shaw could be a member of the Invisible College!
The Ship in the Ice
This shot supplement is not affected by time period.
Artifacts & Enigmas of the American Revolution
All of the historical events related to the relics and puzzles in this supplement have happened by the time Indy is born. It is fun to imagine, though, the excitement that could arise regarding these items after the events in Dial of Destiny, when an old but not retired Indy is present for the bicentennial celebration of American independence, before and during 1976.
Ritual Magic
This short supplement is not affected by time period.
Artifacts & Enigmas of the Knights Templar
Similarly, this supplement is chock full of material that would fit easily into adventures and campaigns. Additionally, the Templars can be an additional faction that is involved in the conflict. They might be seeking revenge against the Vatican, or they could be promoting the fighting in general and taking advantage of it in order to acquire relics and lore for themselves.
Pandemonium
Because it assumes that adventures and campaigns are using the High Magic style of play, and focuses on demons, this supplement may not be appropriate for the world Indiana Jones.