lftp mirror function, ruined user:group on remote, cant delete files
 

Hello,

my lftp command to upload files to a remote host was:
mirror --reverse --delete --only-newer /here/ /there/

now i have some files i cant touch anymore, they are chmod:0777.
user:group is: www-data www-data
it should be: w00fdd28 w00fdd28

In the lftp manual i found 3 possible commands to fix the owner rights, but there are only "owner" related commands for the mirror function.
They are: --allow-chown --allow-suid --no-umask

I am not familar with user:group stuff. Can some one tell me what to do?