There are a number of differences, Stagger feed, Center Feed, but when asking about latches yes there are 3 different designs. The one with the plastic Shepherds Hook as you call it has been superseded by the new model that has a push button on the magazine. The other type has the latch lever actually in the bottom metal.
I have a newer 110 with the plastic stock that also has molded in bottom metal. On this one the new model mag works but the old style will not latch in my stock.
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