samba - Apr 2013 - Is there a guide to "fsck" a samba3 passdb.tdb?

I've come to realize the underlying cause (at least one) for my
contemplating suicide (not quite that bad yet) because of the classicupgrade
process. It may be that my very old samba3 passdb.tdb needs to a get a
"fsck". if this were a filesystem, no problem but I don't know how
to
approach recovering the integrity of the passdb and other samba3 tdb files.
I'm hoping there is a tool or guide I have not been able to find.

Could I please get any of:
1) A how-to clean up a passdb
2) A link to a how-to clean up a passdb
3) A warning that it's futile and end it all, or just manually migrate
things to a brand new domain
4) A how-to or link to a how-to for another approach
	a. An example of creating a new server, joining
	   it into the existing samba3 PDC let all the
	   valid info replicate, then promote the samba4
	   server to the primary, retire the old one.
	   Or will a messy passdb and other files make
	   this just another propagation of historic
	   nastiness from the problematic samba3 files??
5) An opinion on if I should give up on using my beloved linux server for
windows networking and drink the MS coolaid...

As always, any advise is appreciated.
	Thanks,
          -Stephanie