'I suppose in the perfect world, the decision would be made for them with the HO and PITO preparing a well researched short list to choose from..'
The HO and PITO did try that logical step with a document that listed all the salient numbers ... it was not the first of its kind, such a deal started in the 1980s, but there were complaints over the new document that covered all the new generation helicopters [fixed wing were dealt with in a separate document]. It was not Conkin & Dekker but it went a way towards meeting a need.
Unfortunately, although given numerous extensions, one company was unable to submit the flight test numbers in time and complained... as a result the HO walked away from the idea ... although an initial version appeared it showed big gaps for that one type [presumably for filling in later when the numbers were available!] and they quickly dropped the document so as not to offend! They never tried again.
So, with the lack of information, who is offended now?
Gearboxes
I am unsure of the exact situation currently but I believe that because of the spares supply situation gearboxes were being overhauled in Mesa rather that being sent to Kawasaki or offered as a straight swop. Part of the reason for that is/was the credit situation between MD and Kawasaki. The result is that a major gearbox fault can lead to the operator waiting for the gearbox to travel to Mesa, be rebuilt and returned. It all takes time. Maybe someone can update that information.
There are Explorer's out there with original and long time in service gearboxes but I am aware that at least one operator likens the situation to a cat on a hot tin roof....
Will it or won't it ....