Hey, I'm all for recycling useless junk into usable, worthwhile things, but just so long as these worthwhile things are things I might actually run out of and therefore need to make more of (like bombs, doctor bags, weapon repair kits, etc). There ought to be a practical reason for making the same thing over and over and over again at a workbench besides selling-for-profit, at least, IMO.
By all means, put the Rock-It-Launcher in the game. I'm not at all opposed to that. Just... leave it lying around somewhere for me to find, or whatever.
And I agree that the weapons should at least have one in-game already pre-made so players can obtain one without having to make it (they may lack the proper skill level to make the item, such as a high Repair). Plus if one does not take Jury-Rigging and does not want to pay for repairs having the ability to make a replica weapon to sacrifice to the one being used would be very useful, and can save on having to use a WRK on it.
Little Bear's has one flaw in his argument. FO3 had the recipes and the in game version's a;ready made. one was in a random in counter which was a guy with a railway the other was Vance the vamp clan leader who had a shishkebab, Both weapons in game both as recipes as well. I say they should add that system again. Personally I want the recipe more than an NPC having it as not everyone should know how to make the weapons. I.e you need the schematics so what Obsidian and Bethesda want to say is that a tribe of uneducated and savage tribal and lobotomized insane psychos can both figure out how to make a weapon out of random crap but a scientific genius that my character is cant put 2 and 2 together???
I do remember http://fallout.wikia.com/wiki/Laszlo_Radford, and yes it would only make since that if people with little technological knowledge or lack of a brain can make something like a Shishkabob that we could could also do so.