Conrad used the Twin Commanche as a personal airplane after the record flight. It still had the tanks. I don't think anyone knew or cared what his gross weight was. If he was in NY and wanted to go to CA his inclination was to put in a bunch of fuel and go nonstop. TC will go coast to coast on a bit over 200 gallons, with IFR reserves.
Another interesting thing is that on the single and twin Commanche's the tip tank fuel gets a "free ride" gross weight goes up by the weight of the tanks and fuel. Only 30 gallons so not a big deal.