Not sure why you don’t see more 58 Kodiaks, but perhaps the reason you don’t see as many 60 Kodiaks is because some of the “available” production time was used to manufacture 1960 Kodiak Deluxe and Kodiak Special Deluxe bows (new models for 1960)
Consider the radical change in design and use of exotic woods on the 59 Kodiak. Prior to 59 it was maple or maple for riser wood (boring). 59’s were great sellers and it’s apparent that archers of the day ordered a pile of them. Knowing how similar the 60 was to the 59, Bear Archery probably stepped back production of the Kodiak and put that time in the new model KD and KSD.
My question is, why didn’t they keep going with the Deluxe and Special Deluxe models which are among the most beautiful bows ever produced by Bear Archery.