The problem with small worms in the "logs" in the log buggies surfaced in
about 1954 when the buggies were first introduced by Model Engineering Works.
Following an interesting letter in Model Railroader, MEW announced they would
fumigate the logs. But they must have later stopped, because when I assembled one
in 1965, I had the same problem.
I remember cutting branches from some tree (but don't recall what kind) that
made perfect logs for Kadee's disconnected logging cars. Someone sent a letter
to MR not long after the disconnects appeared, saying: "We [in Washington
state] grow LOGS out here, not fencepost splinters."
John C. La Rue, Jr.