Hello there… I noticed this - personally I think there isn’t much recorded by the groups you stated except for ‘Composition of Sound’ I once managed to download through Napster - the recording was very very poor and please correct me if I’m wrong, but that sounded like Dave already singing…
From all of the official sources COS were guitar-based trio, nothing to do with synths at the time… But I guess their musical activities were more on a gig basis than actual recordings… Besides ‘No Romance In China’ and ‘French Look’, there is also a mention of the band ‘Norman & the Dwarves’ in which, I think, Martin was involved… Like with the rest, I personally doubt any of it exists in considerable recording form…
I happen to have a decent version of one of DM’s early demos, ‘TV Set’ - i’ll try and put it on soon if you’re interested… It sounds quite authentic pre-Depeche - is it Vince singing? (anybody?)... there was also some info on early recordings by Depeche - ‘Addiction’, ‘Price of Love’, ‘I Like It’, ‘Tomorrow’s Dance’, ‘Reason Man’ and ‘TV Set’ - that these were supposedly written during COS days… Cheers.