I can assure you that the round from Silver 'Round the World you that (AKA - the Six Flags of Texas, 1986, mint mark CSM) with was produced by Colonial Coins, Houston TX. I personally interviewed Dr George Vogt, owner and interviewed eye-witnesses who have observed that round being pressed in his Houston TX shop, in 1986.
The round below from your site (1 Ounce - California Crown Mint (Texas Sesquicentennial) - United States – Numista) , the mint is not known. I am working to document the mint for this round now. It is possible that it is California Crown mint, since the mint is current not documented. But there is no evidence to support this mint ( at least that I am aware of).
There are 6 in the series:
There were multiple obverses, including the one you show:
Using this conversation as the source I have removed the mint.
Exonumia covers many different areas, and a referee can only go by the information provided by the member when the items are submitted in many cases. I was not the referee at the time this item was submitted but to be honest I may have accepted it as it was submitted since the page as the source had one side that was the same. Luckily this discussion is now linked to the page for others to see and add to the discussion as well.
Thank you for sharing your knowledge and research into this item.