I REALLY wish all of us experienced winemakers would stop telling people to use copper pipes, copper wire or pennies to cure H2S issues! It is a BAD practice because you can add toxic amounts of copper to a wine. Remember--wine has acid in it and reacts to the copper.
ALWAYS use Redulees when you have post-ferment H2S problems because it has only a NOMINAL amount of copper in it to resolve the problem. If the H2S is severe, and the Redulees doesn't cure it, then you go to copper sulfate.
We should teach GOOD practices to new people, instead of teaching DIY practices.
As an obviously experienced wine maker you have made some good points. Reduless is the best choice by far but it is a relatively new product.
Before it was available, the major treatment for H2S was with copper or copper sulfate. Back in those "old days" wine makers of small batches often cured H2S by racking through a clean, sanitized copper pipe or stirring it with a copper pipe, then splash racking.
You wrote of copper being toxic. Copper sulfate? For solving this problem, over dosing with copper sulfate can become dangerous and not just ruin a wine but turn it into a poison very quickly.
Pennies aren't practical for curing a carboy loaded with H2S, but they work great for testing for it. A couple clean, shinny pennies in a cup of that wine, stirred for several minutes then smelled will tell you right away if the problem is really H2S and not something more severe.
People have been making wine for years and years and they have not always had a pot-load of chemicals to solve every problem. I have a very old neighbor who makes 5 barrels of wine each year exactly like his grandfather taught him many years ago. He doesn't use any chemicals of any kind but makes some very nice wines. He has no idea what SO2 is. Sure, now we know that's not the best way, but it has worked for centuries and still works.
Again, I also would use Reduless, but if I didn't have any and I were in a hurry, I wouldn't hesitate to use my sanitized copper pipe. I used a copper pipe before Reduless was something I knew about and the wine turned out just fine. It is surprising how well it works.