Looking for this version of GS/OS

[labelas@hotmail.com (Labelas Enoreth)]

Anyone out there have disk images or archives (though .sdk or DiskCopy
images would be beautiful) of any or all of the versions of IIgs System SW
4.x and 5.0, 5.0.1? I once heard there was a database of all the versions
of GS/OS and ProDOS 16...what is the name of this, and/or where could one
find it?
...I've managed to find 5.0.2-6.0.1...and now I look...downwards, I
guess...call me a completist if you must.

Oh yeah, and I've found a bit of software that is in .img or .image
format, but does not seem to be in any disk image format I've ever seen
before (not any of the Mac-based ones, at least)...I've seen images in
this format before, but does anyone know what utility I would need to
re-diskify them? I think a lot of the CP/M disks are in this format, if
it's any help.

<Hoping he gets a IIgs for christmas...>