Hi Luis,
the keyfiles are different ones and not compatible.
Please note: Do not rename or edit the t2k files. If you damage the data it can lead in unpredictable results like broken songs, broken patches or crashes.
If you own Icarus2 there is no need to use Icarus1. v2 is 100% downward compatible and can do everything that v1 can do.
Best Regards,
Markus