I am actually quite interested in Parsons’ death in Mexico and it is something I have looked into quite a bit. One thing that might interest you is that I believe Parsons may have been killed in July of 1865 and not August as so commonly mentioned in most accounts. My reasoning for this is based upon several factors, but I have also heard that there is a newspaper account of Parsons’ death from July of 1865, dated well before any other mentioning of the incident. Currently, I am still trying to get my hands on a copy of it in order to confirm that it is indeed dated before Parsons’ alleged death in August.
Anyway, I would be glad to share any info I have on Parsons that might be of interest to you. I would likewise be interested to see any accounts you may have collected on the matter.