Just took a look around your port, I have a few comments.
- Change the license line Makefile to indicate the version of the GPL the program is under, GPLv2/GPLv2+ or GPLv3.. etc.
- SCons Handling is a little nasty, fortunately there is a better way to handle it in the ports system.. you can refer to port-modules(5) for more information, and you can search the tree for other ports using it for further reference.
- There is an extra newline at the end of Makefile, and I'd be very weary about compiling with -fomit-frame-pointer and no debug symbols.
That's all I can see for now, but as well as the other man page mentioned.. be sure to read
bsd.port.mk(5) for further insights into the ports system.
Hope that helps.