Your knowledge is incorrect. The 1.3.0 source is available[0], and 1.3.1 should be soon[1], they have not dumped them in the public repository is all.
> I wonder whether it's a complete rewrite from scratch or whether 1.3.x still contains patches from external contributors and whether they agreed that their work be sold for money.
I'm not sure that has any relevance. It would if Growl had changed its license (they have to agree to license changes to their contributions, unless they ceded their copyright to the project or project owner), but selling the product is independent of that. It can be seen as a dick move, but it's still independent.
> I wonder whether it's a complete rewrite from scratch or whether 1.3.x still contains patches from external contributors and whether they agreed that their work be sold for money.
I'm not sure that has any relevance. It would if Growl had changed its license (they have to agree to license changes to their contributions, unless they ceded their copyright to the project or project owner), but selling the product is independent of that. It can be seen as a dick move, but it's still independent.
[0] http://code.google.com/p/growl/source/detail?r=9831a92b05b20...
[1] http://groups.google.com/group/growldiscuss/msg/0793d15920fa...