I hope you get to hear back from the original owner's son.
If not, Salamanca looks like a beautiful city and province to visit one day.
By my calculations 10th June 1969 was a Tuesday. Would there have been many weddings on a Tuesday?
Maybe you could plan a holiday and do some sleuthing in the public records department.
That kind of thing would certainly keep me amused.
In a similar way though if you never actually found any more out I'd still find the speculation and wondering interesting.
Edit:
Ok, you've got to go to Salamanca.
😀
This was added to the 'new' cathedral (started in 1513) in 1992.