Forget that they're elderly. I'm 67.
You don't have to pay for their naivety!
You also don't have to pay $25K, when it's really worth $18,500
You've actually done some of their homework for them.
Give them a copy of the JOC report for free; tell them that you may be interested still - but you need to think about it.
If in a week you call them or they call you, your physical scrutiny will be the next step.
And hold off on your final offer until then.
I'm telling you this, even if the old lady is my godmother's cousin.