As you might have guessed, they go by pairs (.dum + .ins). Just drag and drop any .dum along with the .ins on DP, for example. Can't say about other players.
You overestimate my knowledge regarding amiga formats

I didnt know that one file (.ins) was the sound data (sort of sample storage I guess) with other files being the instructions sets (sort of... I guess) that could load these tunes correctly.
OK. Thats a success, I've loaded these tunes you transmitted into Deliplayer and XMplay. They play well!
Me and my old buddy thank you for your help

!!
Oh, there's one question, The G2.dum tune seems to be rendered with tempo accelerated, do you know the reason? Additionnally if you have any doc/links/info about how to merge these files into generic mod formats (if possible), I am interested!
Thanks again Asle!