The 72 pattern is the largest Case folding pattern there is at 5 1/2″ closed.  Most collectors are familiar with the stag handled “Bulldog” 5172 pattern of the 1960s but it was first introduced in the 1920-40 Tested era in green bone, celluloid, genuine stag and other materials.  The ultra rare “Cases’s Zipper” switchblade knife was a 5172 pattern as well.  The aforementioned Bulldog issue features the Bulldog etch on the front of the blade and will say “Hand made in the USA” as well.  Most of these knives were issued with a walnut presentation box with felt inside and were produced in the mid to late 1960s.  In addition, the 5172 with stag handles was made for the 1976 and 1977 Case Collectors stag sets.  A version with wooden handles (P172) called the Buffalo was also issued in the 1970s.  See some of these knives below.  I appreciate any traffic from these links as I earn a commission when an item is purchased, at no extra cost to you. THANK YOU!!! – Jesse,