I did a few more probes which you might be interested in.

First, I tried a transfer of the 16.207.IN-ADDR.ARPA zone:

$ named-xfer -z 16.207.IN-ADDR.ARPA -f temp -s 1 primary.ctonline.net
named-xfer[2019]: [207.16.240.12] not authoritative for 16.207.IN-ADDR.ARPA, SOA
 query got rcode 0, aa 0, ancount 0, aucount 9

which is not surprising, since if I ask uunet:

$ named-xfer -z 16.207.IN-ADDR.ARPA -f temp -s 1 AUTH00.NS.UU.NET

I get a complete file back.  The problem is, in that file is your class C:

240             IN      NS      auth00.ns.uu.net.
                IN      NS      auth50.ns.uu.net.

and if I get 240.16.207.IN-ADDR.ARPA from uunet:

$ named-xfer -z 240.16.207.IN-ADDR.ARPA -f temp -s 1 AUTH00.NS.UU.NET

I get back:

$ more temp
; BIND version named 4.9.3-P1 Sun Feb 25 14:04:07 EST 1996
; BIND version root@porky.redhat.com:/usr/src/picasso/BUILD/bind-4.9.3/named
; zone '240.16.207.IN-ADDR.ARPA'   last serial 1
; from 198.6.1.65   at Sat Sep 21 01:07:02 1996
$ORIGIN 16.207.IN-ADDR.ARPA.
240             IN      SOA     auth00.ns.uu.net. hostmaster.UU.NET. (
                960118 21600 3600 1728000 21600 )
                IN      NS      auth00.ns.uu.net.
                IN      NS      auth50.ns.uu.net.

which says nothing about your ips.

Note that if I do a named-xfer of the 240.16.207.IN-ADDR.ARPA zone
directly from your server, I do see that you have the records set
up, but this won't help anyone over the Internet at large.

World | Inch