Well Dawg, I was not part of this conspiricy about log cars the first time around but I'll try to help you.
Perhaps wood will work fine in O scale -- I can tell you it's not so hot in HO. I built 20 HO skeleton cars out of mostly basswood, they had brass bunker supports & straps & cheese blocks, but the main ingrediant was wood.
They ended up looking super , but you can't run a string of them empty if there is any curve in your trackto speak of. they will pull right off the track & form a straight line .
I had to run them always full & with weighted logs at that, I was using licorish root logs & had to drill them & put some lead in. Learned real quick that NMRA has weight standards for cars for a VERY GOOD REASON ---- soon as I got them about as heavy as standards call for they were fine.
By the way , if you do build them , when you weather & paint them , a bit of cigarette tobaco ( little tiny flakes) secured to the bunks or main beam with a fix of diluted white glue does a Great job of looking like little bits of bark residue left on the car. I've never seen a real log car but I just know that some bark has to get scraped off & left behind.