Only have time to address one side of this many sided coin - reproduction parts for 240/260/280. Most every time I reproduce a part I first have to give a LOT of thought about how long will it take me to break even on my investment. If I have to invest many, many thousands - like in the case of my interior mirrors - how many years, not kidding here, will it take to reach scale given the TINY market I serve. It's always a decision reached after a lot of sweat has been expended. Have been working on and off on reproduction battery cables for a number of years. My investment will be HUGE. Will I live long enough to reach scale? Stay tuned.
Interesting note - reproduction 240 parts sell at about a 25 to 1 ratio to reproduction 280 parts.
Finally, Nissan doesn't discontinue parts out of meanness. They do it because the parts aren't selling. They couldn't justify continuing those neat under hood trouble lights because they didn't move enough of them even at about $30.00 each!! Try to find a new one now for under $250.00.