I have always been able to buy the basswood comb honey section boxes from Walter T. Kelley in Kentucky (although I noticed they were unavailable from many other sources).  I suppose they still sell them.  Kelley's never used to have a web site, but I was just checking and it seems they have
one now.  I found a reference to the cartons (boxes) for the basswood sections on their website, but I could not find a reference to the section boxes themselves.  Either I did not look hard enough, or they are not listed on their website, though I think if you will look at their printed catalog you will find them.

Layne Westover