Since I've found an other MWR fellow member here (triple cheers for Scotland), how about a short review on my very last arrival for him Hamilton G.S. (stand for General Service), tropicalized for harsh overseas climate... ... including special features as shown on its caseback... (For the records, 1 oe (oersted) is around 80 A/m ) ... not to forget its S75S hacking caliber with a dust cover. Below is a list edited by S13313@MWR 1) Hamilton 6B 9101000 - Cal. 75 (n/hack) 2) Hamilton 6B 9614045 - Cal. S75S (hack) Number 1 and 2 are British Royal Air Force issued watches. The “Hamilton 6B 9101000 Cal. 75 (n/hack)” conforms with MoD specification DEF-3-A (dated 20 October 1959) which has the NSN 6645-99-910-1000. The “Hamilton 6B 9614045 Cal. S75S (hack)” conforms with MoD specification DEF-3-B (dated September 1966) which has the NSN 6645-99-961-4045. DEF-3-B superseded DEF-3-A, and a major change required was the “inclusion of a device to arrest and release the second hand”. (source hq sandman ute @MWR) 3) Hamilton GS Tropical - Cal 684 (hack) 4) Hamilton GS Tropical - Cal. S75S (hack) 5) Hamilton GS 13-24dial - Cal. S75S (hack) 6) Hamilton GS Commercial - Cal. S75S (hack) 7) Hamilton GS KA Mark - Cal. 684 (hack) => Kenyan Army 8) Hamilton GS ADDF Mark - Cal. 684 (hack) => Abu Dhabi Defense Forces (?) Mine is n°4 and wasn't issued to military forces it seems... " Hamilton G.S. ["General Service"] watches were specifically made for the UK's General Services. They were actually issued to Government personnel, that were not Military. These watches were used by a number of Government agencies overseas, Foreign and Commonwealth Office aid groups helping with education and health stuff like that from the mid 60's to the late 70's.They also acted as a cover for a number of former military men who helped nations organise their own security and law enforcement on behalf of HM Government. " (source antiquevintagewatches.com) Anyway, these watches have proven themselves to be trusty in every harsh occasion 36 mm wide excluding crown, fixed bars, the watch share the same case as in the well known IWC Mark XI...and is sometimes refered itself as the Hamilton Mark XI, because it was issued at the same time and to the same specifications as other watches designated Mark XI. No wonder I'm very happy to wear one as I'm written this down Hope you've enjoyed it (and I'm well aware I won't have tons of readers... I know, once again, I should have reviewed my Omega CK2444 instead ... soon ) Fred