One thing though is that the source package should probably be renamed "ocaml-gen", I think "gen" is too generic and can potentially conflict with other things.
Have you considered putting your Debian packages on Alioth git rather than github? We have most of them here:
https://anonscm.debian.org/cgit/pkg-ocaml-maint/packages/
(This is also useful to see what naming conventions are being used.)