Please ignore that . If it stars with a K it would be KB which is 1959, . Can't quite make out the bore size but as the chamber is marked as 70mm then the reproof must have been after 1985. after 1990 all measurements would be in metric. We could do with some clearer pictures if possible .Or tell me what the bore sizes are stampped It appears that there might be 3 sets of marks but could be mistaken .
There will be 2 letters on the date stamp the number is the view res ID and is irrelevant.
Joe the re proof pressure is 850 bars that superceeds the older otns per sq inch
