As with other replies re this topic , I have never sectioned wood
however histologists are famous fro procrastination so:

When wood veneers used to be made they were actually turned on a
modified lathe and the sections made using a long knife similar to
microtome knife. For hardwoods such as mahogany the wood was first
soaked in warm water or steamed to soften it. Most of the veneers were
however longitudinal rather than cross sections.
In the case of hard woods and with some conifer cones, sections were
made by cutting one side, polishing with abrasives, glueing this side to
a slide and then grinding down the other side to achieve a thin enough
section i.e. similar to the process that we use for routine ground
sections of teeth.
With a small enough piece and one able to be infiltrated, it should be
possible to embed in plastic and prepare a section or a ground section.
Time consuming yes - but how many people would be able to boast to their
grandchildren - well I was not only a histotech but I prepared unique
sections of wood?
Barry