In the records you hold, are there any m84/86/87 actions with the same numbers?
I'm wondering if this series of rifles are all numbered consecutively, with only the letter designator to indicate if an action is a single shot or magazine fed?
Marlin did this during the 19th century - m.1889, 1891, 1893, 1894 and 1895 actions are all numbered together within the same serial group.
whereas Winchester ran each action as their own serial sequence.
probably the main purpose for use of this system is to inflate production numbers by giving the appearance of much higher production for each individual model.