The 1851 census where one son is still living, is Tynyweun Farm. It's next to another family at same address, but there's insufficient info to be able to locate it from this, since the 2 household lie between a few pages listed as Pensarn and a few pages listed as Nebo (no specific properties or streets named).
However, I found it on the 1851 census and it's listed before and after several properties that might allow it to be pinpointed.