Package libnss3-1d:i386 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source
E: Package 'libnss3-1d:i386' has no installation candidate
Your suggestion of using MCUXpresso works for me. Installed without any problems and works fine on Ubuntu 16.10, I guess this will be the way forward for LPC development. Could not find a satisfactory solution to 32 bit library installation issues in LPCXpresso on 64 bit Ubuntu 16.10.