Lots of drilling and riveting. One guy brought in an old short body to the shop I was working at and Al quoted him a big number, so it must have been a *****, at least a few weeks worth of solid work. I remember even back then when planes were worth something thinking the repair unviable, and I assume so did the owner. I didn't get a detailed breakdown on it, but the shop specialized in structural rebuilds and Al wasn't expensive, so I'm assuming it was an ordeal.