move imap mail to new server

[James]

I tarred up my Maildir from one server and untarred it on another,
I had hoped it would work,
It partially does.
It has all my messages but doesn't show the subdirectories in Thunderbird.

Maildir# ls -l .INBOX.car
total 44
drwx------ 2 rjl  1000  4096 Feb 15  2014 cur
-rw------- 1 rjl users 17408 Jan 18 02:10 dovecot.index.cache
-rw------- 1 rjl users  1040 Jan 18 02:10 dovecot.index.log
-rw------- 1 rjl  1000    23 Aug 26  2011 dovecot-keywords
-rw------- 1 rjl users  1683 Jan 18 00:20 dovecot-uidlist
-rw------- 1 rjl  1000     0 Aug  4  2011 maildirfolder
drwx------ 2 rjl  1000  4096 Aug  4  2011 new
drwx------ 2 rjl  1000  4096 Feb 15  2014 tmp

Maildir# ls -l .INBOX.car.Enterprise/
total 40
drwx------ 2 rjl 1000  4096 Jul  3  2013 cur
-rw------- 1 rjl 1000 20480 Mar 20  2014 dovecot.index.cache
-rw------- 1 rjl 1000  1824 Mar 20  2014 dovecot.index.log
-rw------- 1 rjl 1000   212 Jul 10  2013 dovecot-uidlist
-rw------- 1 rjl 1000     0 Jul  2  2013 maildirfolder
drwx------ 2 rjl 1000  4096 Jul  2  2013 new
drwx------ 2 rjl 1000  4096 Jul  5  2013 tmp

Thunderbird displays the files under:
.INBOX.car/cur/

but not .INBOX.car.Enterprise/cur

Is there any way to rebuild the subdirectories?