Where to buy Seamaster Master Coaxial Adjustable Clasp

[KeepTicking]

Hi guys,

I'm looking to buy the adjustable clasp from the Seamaster MC, but I can't find any for sale on Otto Frei. Does anyone know where I can find one and how much it will cost?

I want to put it on my 42mm PO 8500. Can anyone owning a Seamaster MC confirm that the bracelet tapers to 18mm (same as the PO), so that it will fit the standard PO bracelet? I've seen a post where someone has fit the clasp to a PO GMT, but I'm not sure whether that bracelet tapers to 18mm, bc I know it's 21mm at the lugs.

Thanks in advance!!