Hi sorry only just seen this I don't seem to have gotten a notification.
Anyway here's the history of the gallery.
The gallery was originally Photopost Pro and bridged withVbulletin 3. In about 2009 the gallery was then migrated to VBGallery (the all enthusiasts version) and at the same time we upgraded to Vbulletin 4 suite. The reason for the migration was that the pro version sucked and was badly written whereas the VBgallery version was naturally good.
We've run the gallery since but I archived it (shut down comments and uploads) as we simply couldn't get bug fixes and patches and the gallery was vunerable.
So the VBgallery version is 3.02
It seems that the album structure is fine and some of the comments are missing, but at the moment the VBgallery directory shows 85,307 files in the main album directory which is /public_html/photos/files
and the dragon gallery says 8,307 files in /public_html/dbtech/gallery/images/upload
Like you said the new gallery builds the thumbs, but the difference is large. I appreciate that PhotoPost galleries are a nightmare for you as it seems that they simply dumped images random, but the old gallery is still in working order. I have tried to import the images again and ticked the box to clear the previous images.
The gallery and vbulletin are hosted on a shared server with WHM and Cpanel with unlimited (well a lot) of disk space and memory.