I would have to put both of these fellows in the professional category. John McDougall has a steady stream of Vincent engines arriving for rebuild from points all over the world and has been doing this for many years.
The total time required varies greatly. For example, John did a total rebuid of my Vincent engine/ transmission in just 73 hrs including some custom machining to incorporate numerous fixes for common oil leaks.
Right after my bike he did the engine/trans of an Argentinean bike. Quite a number of Vincents went to Argentina as they were the Police bike there plus many were sold to the public. These bikes are generally in horrible shape, having been rebuilt by the local blacksmith with homemade and very crude parts.
Where my engine required a one page parts list for rebuild and 73 hrs, the Argentinean engine required seven pages of parts and 315 hrs of labour,much of it repairing crankcase threads, broken bearing housings etc.
John repaired 37 stripped bolt holes on the engine, plus a lot of other damage. Probably if it was anything other than a Vincent engine it would have been thrown away, however due to the relative rarity people now seem to restore Vincents from tiny bits of Vincent DNA.
For speed, I don't think many could surpass Dan Smith. He has spent his entire life as a machinist, starting with an apprenticeship in the Shipyards and eventually running his own firm, which he sold a number of years ago.
His sole purpose for taking the machinist's apprenticeship was to eventually become a motorcycle machinist. He has definitely made the grade. Here is another shot of his AJS creation
http://www.khulsey.com/motorcycles/zoom ... _1936.html
In addition to the engine trans, Dan built most everything else for the bike except the frame, since he had a correct AJS frame on hand. For example, when it came time for the exhaust headers and mufflers, he went down in the basement and produced them one day, then sent them out for chroming. Same with the fuel tank, although it took much longer.
I should point out that his basement shop is full of automated state of the art machine shop equipment specific to motorcycle reconstruction. Without that he would be less proficient.
The other article incorrectly described the AJS as SOHC, but you can see by the photo it is a V4 DOHC. What a complicated engine! By comparison a Serives A Vincent twin will be easy for him.
As you say, 200 Hrs is very fast for a total resto. I know of a Vincent Restorer in the Northern California area, more of a talented hobbyist.
His finished products are excellent, however he does not have the benefit of a lifetime in the trade as our two local fellows do. He estimates that the average Basket case resto takes him about 500 hours to complete. He also has people in line waiting for his services.