The same kit can "almost" be used. The piston head o-rings are different sizes. The stem o-ring and hp seat are the same; however, MK200 piston head takes a -023 o-ring where the MK2 uses a -022.
From the Scubapro website (timeline):
The MK200 is a slightly different version of the MK2. It has a piston head that is slightly larger than the MK2. The MK 200 has three low pressure ports, one high pressure port, a large yoke and black knob with a MK200 sticker. There were two versions: the first version, 1988-1991, has an S.P.E.C. cap and an optional rubber S.P.E.C. boot was offered for this regulator and would also fit the end cap of a MK2 first stage.
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