I've just added the crack intro to Kestra :
http://kestra.exotica.org.uk/demo.php?id=27249 I searched for it after your comment, in fact

.
So, the music is by
Leffty/TRSI. It's in Sonic Arranger format, hence not on AMP.
You'll find a download link on the Kestra entry.
Hi Sylvain,
wow - you exceeded my expectations!
I went over to kestra, downloaded and was able to play that file. From the sound I should have known it, but having no experience on Amiga, am still a bit surprised it's a chiptune and not a MOD. Well, learned something - better late than never.
Anyway thank you very much for your fast and correct response.
Nils