Question about moving second hard drive from OSX Server 10.5

Okay, this may seem like kind of an odd question. I've got an old G5 Tower (1.6GHz) that's still kicking. I bought it new. Over the past couple years I've been using it more or less as a simple file/print server. I had the OS installed on one hard drive(160GB), and the second, much larger hard drive(1TB), I was using for exclusively for file storage.

I'm going to retire the G5 and put it up for sale. So I dug the old/original 80GB hard drive that came with it out of the closet and zero'd it out and did a fresh install of OS X 10.4 (Tiger?).... I had a few issue but finally got it running.

Anyway, I don't know if this could be a permissions issue on the 1TB drive or the fact that the G5 is now running 10.4 but I can't access the hard drive I left in the system (the 1TB drive used for files only). I can see this in the disk utility but I can't seem to access it via the finder.

I'm running one last x7 zeroing on the free space of the old 80GB hard drive before I pull it and put the OS X Server (10.5) hard drive back into the system one last time.

My plan is turn an older core 2 duo iMac I have into a server, buy a firewire hard drive enclosure and install the hard drives I had in the G5 into that enclosure and have it connected to the new iMac server. Since I haven't bought the enclosure I can't test this out, but I'm concerned I might run into the same problem when I place this archive of files into said enclosure.... hoping I can read it just as if it were in the old G5 again running 10.5 server.... but it won't.

Anyway, would anyone have any suggestions about this, or have a clue why the 1TB hard drive won't show itself in the finder, although it shows up perfectly fine in Disk Utilities? I'm not at all worried about the 160GB hard drive as I'll wipe that and probably use it exclusively for TimeMachine backups. I just don't want to find myself in a position where I can't access all the archived files/graphics/etc on the 1TB drive after I offload the G5. Will probably go ahead and wait to sell it until I buy an enclosure.... but I just wanted to try and understand what my real issue might be.

Sorry if this sounds at all confusing. Thanks for your help and/or input if you've run into this before.