I found Hume's work on the Online Library of Liberty, in case that's accessible to you.

oll.libertyfund.org/titles/hume-...

Ah, I see. Here's the info about them, in case you can find them elsewhere:

"The Thirteen Principal Upanishads" is by Robert Ernest Hume.

The "112 Upanishads" translation is credited to "Board of Scholars", edited by K.L. Joshi, O.N. Bimali, and Bindiya Trivedi.

See if either of these fit the bill:

"The Thirteen Principal Upanishads":
archive.org/details/thir...

"112 Upanishads"
archive.org/details/k.-l...

Trying to hang in there! Good to see you're still here, Hélène.