I don't know if you will find much help as someone has already said the flash is too small (how was this decided ooc?) and the chipset is currently unsupported.
I have seen some GPL sources floating around for "official" firmwares so you may be able to find and modify one for your dlink.
If you just want bridging take a look at http://www.caiozanolla.com.br/blog.php/?p=231 . Its a Trendnet 652 v2 which is based on the same chipset (or at least similar) so it may be pretty simple.
As for the devs, is there any interest in this chipset/platform? I know there are some devices with more flash out there (like the 652 v2 mentioned at the link.) I've got a couple of Airlink 675s coming that I can check the size of ram on and could potentially donate one of them.