Hello Hugo !
First of all , excuse me my little late answer but your question is the first question since a long time here in this message board and I am so so happy and glad about that :--))) Thank you for your question . I have not thought that anyone writes here a message .
I have found some URL´s : all the following links are showing if you click on them the cheat codes for Indy Jones and the last Crusade for the PC version :
on the above link there are even Hack Codes : Hex edit INDY3.EXE ( that means that you have to change or to do something with an Hex Editor with the INDY3.EXE but I really don´t know how this works )
If you go to this search engine :
an type in this phrase :
"Indiana Jones" +Codes
and click then on Google Search ; then comes a lot of links to cheatz also for other systems like Gameboy , Amiga , Nintendo .
For security here are some PC cheat codes from one of the above links :
Indiana Jones And The Last Crusade
At the title screen, type "iehovah" to enable cheat mode. If you entered the code correctly, the screen will flash. Then, press one of the following keys:
L Level skip
1 or 2 Jump to halfway point in level
I hope this all will help you and i wish you many fun with playing games and all the best for your future !
Friendly Greetings from