Weird ignition timing problem

We were working on the LeMons '74.5 260Z today, trying to start it for the first time in 15 years. A PO messed with or removed nearly every system on the car, so consider it a basket case. After installing 3 screw SUs and tons of stuff that had been removed or hacked, we were ready to start it. After not getting anything, I checked the timing. With the #1 cylinder at TDC, the distributer rotor was not pointed to 9 o:clock, but rather at 7 o:clock. I pulled the distributor to check the shaft position and it was dead on 11:25. I turned the engine until the rotor did point at the #1 plug and it was way off 11:25. I had to pull all the wires and index them one hole counterclockwise. Once I did that, it fired up and ran great. Anyone ever see this before? I know where the shaft needs to be as well as where the #1 terminal is located and this is simply off.

It runs fine the way it is, but I want to know WHY!!

The good news is that the engine sounds great even without the carbs tuned. I never even touched the timing after I moved all the wires. Oil pressure is good and once it was up to temp, we checked compression and got 150psi on all six cylinders. Now it just has to run near redline for 1000 miles on a race track.