Decapitation by guillotine was a common mechanically-assisted form of execution, invented shortly before the French Revolution (although an earlier version of the guillotine, the Halifax Gibbet, was used in Halifax, England, from 1286 until the 17:th century)
Another version called the "Maiden" was used in Edinburgh during the 16:th - 18:th centuries). The aim was to create a painless and quick form of execution that did not require great skill to carry out.
The executioner, after chopping off the head, would hold it up to the crowd. There is dubious evidence that the head could remain conscious for up to ten seconds. The account of Dr. Beaurieux who observed the decapitation of a convict named Languille in 1905, may imply that the head could still see as he recounts "Next Languille's eyes very definitely fixed themselves on mine and the pupils focussed themselves"
Maybe you already have a guillotine attachment for your Bridgeport milling machine? If not I’m sure Andrew Johnson could help you out, he is a fearless visionary, hero, and a mechanical pioneer. And most important, not afraid to decapitate a few historical significant archaeological items such as these Linkerts.
The guillotine was also used in Algeria before the French relinquished control of it... Another guillotine existed in Vatican City, until recent years. It had been brought in by Napoleon's forces during the early 19:th century; and, in 1870, the Pope still claimed the authority to use it. In recent times however, the Vatican has abolished capital punishment in its own jurisdiction, and recent Popes have condemned capital punishment wherever it is still practised. However - the Pope's capital punishment abolition does not apply to Linkerts, or so I hope...