Doesn't old versions of CoolEdit on the PC let you highlight a frequency in a sound file isolate it?
Then it'd be easy to hear the morse code.
Sadly, I don't have CoolEdit as I'm on a Mac and have never found free software that does it.
I've just had a listen to the Designer Grebo mix, and I made out this sequence:
At 0.18: ---.--- .-- -- -.--. (second dot sounds clipped at the start, could've been a dash)
At 2.10: .-- -.--.-- -- -. (first and last dot sound clipped too)
Which according to your translator means nothing much at all!
?WM?
W?MN
But I could've got the spaces in the wrong place. If you add a few here and there the same sequences say this instead:
--- . --- .-- -- -. --. OEOWMNG
.-- -.-- .-- -- -. WYWMN
I think we need to get Charles Babbage on the case, it's beyond my amateur deciphering.