I am sure the quick answer to this is YES.  But more complex than I can explain now on the forum.

A few general guidelines:
1. Think of natural structures the same way you think of relational ones.
2. Create separate database in Sesame to match the ones you already have. Keep all the databases in the same application
3. After the new databases are created you can import data from old system to new databases
4. After the new databases are created you can nest them as subforms.  Create different subforms as needed for each parent form.   There can be multiple subforms on same parent form.  Same database can be a subform on more than one parent form. You can have subforms within another subform.  You can choose different fields to display on different forms for the same database.

More specific definitions needed now for more specific instructions.   Just wanted to give you hope and help you to understand the potentials.

It sounds like you already did your design.   Remember you will be importing into databases,  not into forms.  If they are structured correctly,  I think you can just import from your old databases to your  new ones.   I would do this in a top down process of database links.   As they are imported, the natural links should be created and attach the records to  the correct parents.

Can you show a tree of your databases and forms?

Hi John.

Thanks for the attachment.  I see nothing unusual based on that.   

It would seem that you should be able to import the AccountHolder  into a Sesame AccountHolder database.  Then import the SecurityName database into the Sesame SecurityName database.

If you have already added a SecurityName subform to a form in AccountHolder, you should see immediate results.   If not, then add the subform with Natural links to get the results. (Use Tabs for subforms, even if only one now.  Will be easier to add multiples at a later date).

Then do the same with BankAccounts with a Natural linked subform on AccountHolder

Now do the same with the other four databases , making subforms for each one on your desired parent form(s) in SecurityName.

I generally make Tabs for subforms to eliminate scrolling and to have quick access to other info just by changing Tabs.

But what I suggested here is based on some experience assumptions and may not be so straightforward.  What I would really want to see is the exploded tree of the database and form structures you have created in Sesame.

You can always make a copy of your existing design and try these steps on the copy.   Good luck.

Thank you Bob and Ray!  I know this is delayed, but I haven't died. I am a clergyman and near Christmas and for some time afterward life gets hectic, even though (at 78) I'm 'retired.'  I didn't know I could do the re-parent procedure with a naturally linked database structure. That certainly does solve my problem!
John F