Ed,
you're right, I did not part all the way through, most of it then finished with my thin bladed Japanese saw.
Dave,
Sorry I did not add dimensions. The tallest is just around 8" tall, I'll measure them properly later for you. The Spalting is wide and open, not the usual multitude we'd line we normally see.
It came from one of my Tree Surgeon friends as a big section of trunk about 18 months ago, I cut it and sealed it, just started working some of it. He gave me a Spalted Sycamore log last Autumn as well (okay, I do also have a wood fairy or two).
Les,
I used white Oak as the inset, one of the useful things you can do with 1" boards of timber. A tip, don't try and make the ring completely before inserting it. Make to size and glue in as a disk, then drill through and work your way out to the raised lip.