I'm currently playing the first game but haven't received the grappler yet. I have finished the mission with Alifano and it wasn't given to me in the base. No it's not hiding in my inventory on the slot nr. 6, it just isn't there at all. I would really like to use it though, as it is the heart and soul of the game.
Did you somehow skip any cut-scene? This is something that can cause problems in some games.
Do you have any older saved game that would let you replay The San Esperito Connection? In a game that has multiple slots for saved games, it's always a good idea to keep some, just in case this type of thing happens. Like one new one after each 5 missions.
No I do not have such a saved game but I thought about it and now I know what to do:
I have a saved game where I am a few missions further WITH the grapple hook, so I decided to play till that mission in my saved game WITHOUT grappler, then switch to the saved game WITH grappler. I will lose my liberated settlements and my collected crates, but that's ok. My current saved game is just to bugged to complete the game with it 'cause I do not have a grappler and Kane seems to be buggy, too. She does not talk at all. However Thank you for your time, I really appreciate that and I am honored. I know it's early, but MERRY CHRISTMAS!