I thought that too
Alter is the surname which could be they were Jews too
However....that is a 1955 painting
Most of the artists work is post WWII
And in their pic they don’t look Jewish
So new theory.
Maybe they just liked De Koonig
A lot
Yes, your timeline does indeed discount the Nazi-stolen art line of investigation. The painting also doesn’t seem to be worth what it is said to be worth.
I think Lurkina.n.Learnin in post #10 has a very plausible cause for explaining what went down. My view of Lurkina.n.Learnin’s reason is that it makes sense as an inside job too. The painting had to be kept out of view and the couple were known to be reclusive. Makes sense they were in on it.
We all love a good mystery. I’ll just add that high-priced paintings may be used in money laundering. “Where’d you get all that money? Why, I sold a painting!” John Podesta was in Europe late last year buying up untold hundreds of millions of dollars worth of paintings. Such paintings can be better than cash. You can’t insure cash unless it’s inside an insured bank, but you can insure a painting inside a bank or not.