Cannot decide on project direction 73 Duster 340

It sounds like you're most hesitant about "cutting it up" than anything. I vote build it the way you want which sounds like a mild/street-friendly pro-street look that remains comfortable for cruises. I wouldn't bother trying to go stock unless the car was #s matching everything or close to it. Main thing is... are you trying to maximize sale value and leave it parked most of the time? or do you want a car that is going to leave you with that permanent grin on your face? Only you can really know. You can always do "bolt-ons" for everything and if you decide to go back to how it was then you have that option. You have a duster so its not like you NEED to tub it to get a decent amount of rubber back there if you're running a stock/almost stock small block.