Looking at a couple of other threads, it appears to have been a good weekend for making project progress for everyone.
Here, it was much the same.
Yesterday we replaced the aluminium hard lines and bulkhead between the firewall and the heater.
In doing this, it was easiest to remove the core anyway.
Looking at the stains on the floor under the carpet and on the underside of the carpet itself as well as lots of broken lower dash plastic tabs (as well as the core itself), the core has obviously been replaced at some point in the recent past. Labour may have been performed by a an over zealous gorilla though.
We also did the o rings at the heater end as well.
Far more annoying than that we replaced the really short coolant soft hose between the hard lines between the head and the firewall - super easy to get to but a royal PITA to change.
We also changed one of the rear camshaft seals (the camshaft position sensor side) and polished the drivers door - which now looks a lot better.