Design does not fit anymore on Cyclone II with quartus 13.0sp1

Hello,

I'm using Quartus to compile design for a Cyclone II, the designed was first compiled with quartus II version 6.1. This version is not available anymore on intel website and the only version supporting cyclone II is 13.0sp1.
When compiling the design with version 13.0sp1, it does not fit anymore (total logic element 108%, 308/288 LAB).
I tried various options in quartus software to optimize in area without success.
Does anyone knows how to :
- download quartus version 6.1
- reproduce the same level of optimisations that were available in 6.1 in the current 13.0sp1.

Thanks.