Hi Rick.
My suggestions about file systems are the one that I posted. If I will have to put those (HPFS, Boot JFS and ZFS) on priority order, it looks more interesting ZFS to me, since HPFS has MS patents on it and JFS is close source but AN is supporting it. ZFS can be focused on being an alternative for the future OS/2 file system.
But while there are people saying "don't reinvent the wheel" I say "reinvent the wheel if it is not open source". Close source software is future abandonware to me, even if it works fine today. (Already discussed on the past how open source software reduce the risk to be left "high and dry")
Gordon Letwin, according to wikipedia, is a guy that made millions with Microsoft, so I found it a little bit hard to contact him to request HPFS source code, his OS/2 book, or any other things related to OS/2 to be turn open source/public domain. He seems to be more focused on environmental activism. But I had never tried to contact him.
Interesting historic post by Gordon Letwin, by the way.
If I can choose a priority outside the "File Systems" the priority should be to start cloning more deep components of OS/2 like the CPI API (possible more based on libc library) and a PM/GPI clone (also with more close dependencies to libc instead of CPI). It will require developers with a good understanding of the CPI API, PM API and LIBC. But since I don't do development and do not have money for an army of developers, this is only "sweet sweet drunk talk" for the moment.
Regards