Bill,
Thanks very much for clearing up those points. I do have the two DGJ articles that Oscar wrote as well as some correspondence from him from a few yrs ago. It seems that even Oscar varied the process when he felt something was not working. I suppose that knowing when to do adhoc changes comes with experience.

I did change my etch solution to match your/Oscar's recommendations. In the past, I had read Oscar's recommendation to be a 15% strength solution of FeCl3. I can see from my short experience that 15% strength is way too strong. Thanks again.

As for a source of FeCl3 solution, I found it at a old-time electronics store. You know the kind; dust on everything, things all in disaray. Great store.