Crafting is nice, the only reason I want all old weapons craftable is to give them the origin trait for the respective armory with perks pulled within the weapons frame type. This would add more personalization and unique combos. Of course some people would only use certain metas but I would try to find something others aren't using. Make all in game guns craftable if you get enough red borders for their playlist, aside from outliers like Adept or Exotic. Make all old guns craftable if its within your own personal collections, if they aren't obtainable due to discontinue then only those that had one can make one, keep some FOMO but reduce overall RNG.