Newbie – 10.4.11 ->10.6.3 (now 10.6.4) upgrade with now corrupt keychains

I have looked through several hundred posts and articles here and am not sure where this post should go.
If it is in the wrong place, please let me know (gently) and I’ll change what I can.
—
…short synopsis…
Key chain items migrated from 10.4.11 server have fields no longer in use and the individual non-system key chains have
become corrupt. I cannot return to the 10.4.11 system since my video card died and the Apple supplied replacement would not
boot under 10.4.11. There is no method (I know) to migrate individual key chain items from the migrated 10.4.11 chains into
virgin 10.6.4 chains. I can migrate certificates using ‘Keychain Access.app’, but I have precious few of those entries. I have mostly
(& stupidly) used key chain secure notes to record important system and family information in case I am incapacitated (diabetic).
—
I also renamed a restored ‘xxxx’ key chain file to ‘xxxx copy’ and used it in an ‘Add Keychain’ action so I could
move its items into a virginized chain named ‘xxxx’. However, ‘Mail.app’ insists on reading the ‘xxxx copy’ key chain
when it starts. The old chain name must be present in the file’s data. Even if I am able to migrate all my items, I do not
know how to get Mail to use the entries in the viginized 10.6.4 key chain.
—
…now the requests for additional expertise start…
I have run out of expertise with Apple Support and need to get my data tied down so backups can be made of the
restructured items.
—
I have tried the ‘security’ CLI, but it deletes key chains not listed when I try to set the keychain name using
‘list-keychains -s “” ‘ so that a ‘dump-keychain’ option can dump entries to help me load
the new chains. I have not (so far) found another CLI that appears to be of use.
—
Can anyone help direct me to a CLI or some GUI that will get my currently migrated 10.4.11 data (plus new items entered
under 10.6.4) into virginized 10.6.4 items?
Note: I know almost nothing of ‘keychainmanager’, but I’ve been told by Apple it does little to help my situation.
—
Thanks
…A 10.6.4 newbie with linux/AIX CLI experience…
…But not enough under 10.6 server…