Re: How do I “warrant” art for the long term?
I personally try to use the best materials I can for each job. However, many of my buyers do not wish to spend the added amount to move up to 316 and I use mild steel instead. So, we all know it will eventually rust, but I use thick enough pieces so that they can easily be restored.
I am not of the opinion that electronics would be proprietary, as any half decent EE would be able to re-make or design just about any thing. Unless you are a cutting edge designer doing very sophisticated work, I would view the electronics in the same way as I view a layer of paint. I would provide a schematic, or a diagram explaining the functioning parameters, and that should be enough for your piece to be restored forever. Now, if the actual component are visible and part of the work, then that is another story.
I have worked with electronic components for over 30 years, and know that even the simplest parts will degrade rapidly. Capacitors drift or fail, resistors do the same, IC's need to be handled much more carefully than most people realize, etc. There are ways to over design your circuits to make them very sturdy, but that would be much more complicated.
I think that if you want your sculpture to have a long and prosperous life then you have to make it easy for some stranger in the future to restore it.
If you are using simple binary counters, such as the old 7493 or similar I would just throw in a whole pile of them so that the piece can be restored for a long time.
Another thing would be to pay close attention to your power supplies, and make sure you over design them. Instead of spending $10, you can spend $30 and end up with something that will most likely never burn up (OK, last a long time). Oversize your components for a long life.
Any way, just give them the schematic. I am not sure how you are lighting your displays, but I would put LED's behind something else that is lit by those LED's. LED's will be available for a long time (All house lighting will be LED driven in a couple of decades) but you do not want to have to make your customer find an exact match which will most likely not be available in 50 years.
Well, that is my humble opinion.