I have some old Word files (Word 5, I think), written in mid-1990s, that I can't read in 10.12. Tried current Word, LibreOffice, Pages. Even tried on a PowerBook G4 running 10.5 - no luck. Any tips on how to do this with minimum hassle?
Not sure if this helps but I found word 5 for mac here. https://winworldpc.com/download/1dc2a931-2848-3011-c3a4-c28d587054ef
Always be careful downloading files from the internet. I can't vouch for this site. You will need old school hardware and know how to use the download.
You might be able to open them or at least partially read them with a good text editor. Unless the file or files are messed up, you should be able to read them. I can read Word files from Word 95 and 97 (Windows versions) with my current Mac version of Word (Office 365). Microsoft at one time provided filters that you could use to read old DOS and Mac versions of Word, however, I don't know if those filters are still available. But Google is your friend....
You may try "open" office apps like LibreOffice. My experience in the past is they were more accepting of a wide variety of formats. Free, other than the large download and the time to install.
Dataviz used to have a great conversion program. I forget what it was called. It’s old enough that I’m not even sure if it would run on the machine running 10.5. But that might be a way to go.