No never heard of the MK3 being designated as military, The MK2 was hence the "service" tag , The MK3 supertarget is a nicely made rifle, usually in the region of £250 - £400 depending on condition, Mk2's can fetch very high prices dependent on calibre, condition, Cased, barrel set etc etc , I would look for more provenance of any military connections before spending higher amounts on a MK3, There are some serious collectors on here with far more knowledge than me that may be able to offer more info, I would love to see a pic if it does turn out to be the case .