Hi stuntshell
use pico (or any editor you like) to edit /etc/e-smith/templates-custom/etc/rc.d/init.d/masq/34CustomNAT
find the entry for Mysql
/sbin/iptables -t nat --append CustomNATin -s xxx.xxx.xxx.xxx -d yyy.yyy.yyy.yyy -p tcp --dport 3306 -j DNAT --to iii.iii.iii.iii:3306
change the xxx's for the IP you want to have the ability to connect to your internal server
the yyy are the external ip that you want your server to respond to
the iii is the local ip of the server.
the entry should be there beforehand the only thing you have to do is insert: -s xxx.xxx.xxx.xxx
then copy the whole line at paste it under the previous and edit the -s xxx.xxx.xxx.xxx
do this for each IP that you want to be able to connect to the Server.
remember to restart the masq service
/etc/rc.d/init.d/masq restart
or simply reboot
Don't know if it'll work, but hope

it does.
Let me know what you find.
Frederik