Marchionis, Tapered and Shouldered Blocks

I recently purchased two Machioni Tiltalls on EBay and noted that there was a design change at the "apex" block from a tapered "cone" section (left) to the permanent design that follows today - a much easier to machine squared shoulder.

For those interested in the headless monocolumn that I offer, the "shouldered" and assumed newer iteration (right) will accept the column, if the rather thickish inner bush strip is exchanged for a thinner bushing. The earlier lacks the bushing and I cannot recommend the expense of machining inorder to add a monocolumn.

No doubt there are even more earlier Marchioni design changes and if you have a curious version, I would be happy to post your jpegs and story.  Click on photo to enlarge.