Location makes a difference. Where are thigs roughly?
A dealer is likely to give a low price for machines, a token amount for accessories with the excuse that they are 'part of the lathe' which they aren't necessarily *, and virtually nothing for the small tools. Best if you can interest a local club and offer them all the small stuff for help with the rest. Club members might be interested in the machines.
* The make of machine makes a difference as to what should go with it. The recent far eatern machines come with a set of accessories that older UK machines didn't. There are also specific items like the second set of jaws for a 3 Jaw chuck that must stay with it.
Of course your FIL is still around to advise you on this which makes it easier than for an estate sale.