I say you do it, learn it, and build it! I will also however warn you that this is a rabbit hole with no end. You start this thing and you will be dragging old heavy machines into your garage in no time, as well as selling everything non machine related to buy more tooling. A lathe is a huge component but its all the other stuff that really costs. Tool holders, thread gauges, micrometers, thread wires, dial indicators, magnetic bases, layout tools, special oils, work holding devices and plenty more. Not to mention How to Run a Lathe, and The Machinery's Handbook, and many others. If you want to start this process I would highly recommend going through "That Lazy Machinist" beginners machine course. Its a free course from a great machinist Mark L'ecuyer who taught at a university in Canada for a very long time and is a wonderful resource for learning the correct way. The other great resource already mentioned is Tubalcain on youtube (Mrpete22). From those two, you will know what the next step is and the right direction to go in. I couldn't imagine doing the operations you mentioned without knowing a hell of a lot more about metrology in general, materials, cutting tool geometry, and some basic Trigonometry and whatnot. I'm about a year into learning manual machining and my house and garage looks a lot different than it did when I started! I also don't sleep, and am always VERY busy but that's kinda what it takes to acquire the knowledge necessary. I'm not so interested in gunsmithing however, so your journey might not be as intensive, but probably will be. You wont need my help with the sources listed above but if you do have any unanswered questions at any point you are more than welcome to send me a message and I'll happily share whatever I know. Good luck making chips and be safe! Jesse