Hi, I've run into this also.
I've installed lib16 on ubuntu 12.04.
and isp2 is working for me.
for 32bit version:
sudo dpkg -i libmysqlclient16_5.1.58-1ubuntu5_i386.deb
for 64bit version:
sudo dpkg -i libmysqlclient16_5.1.58-1ubuntu5_amd64.deb
Few years ago I've read that isp2 will coexist with isp3, as I did not have any issues with isp2, didn't know that isp2 is EOL.
it's a terrible place to be in.