[G4] Hard Drive Partitions don't all Mount

[John Sparks]

Hello:
I have a G4 Dual 125GHz MDD 800, running OS 10.4.8.
It just replaced a G4/400, which blew the Power Supply.
I installed the 2 HD'S from the 400,into the empty bays of the
125. One had 3 Partitions set up for OS X, the 2nd had 4
Partitions with  OS 9 stuff. On first set-up all Partitions appeared
on Desktop. Then 2 of the Partitions disappeared from D/T.

Checking with "About this Mac" all appear under "Volumes"
Under 'Disk Utility" all are listed except the non appearing ones
don't show any available space.

I used TechTool Pro and they appear with it and check-out,
however are grayed out. However it does show the number of
files, used and available space.

What do I need to do to get them to mount?

Thanks for any and all suggestions.
John Sparks