sorry for your loss.
If they are originals and your dad bought them I think you can sell without any problem.
(I'm no layer, just used my common sense)
like you said: I think its the same way as with copyrights on books.
copyright means: you ain't allowed to make more copy's of it and sell them to make money. or make copy's and give them away so the author doesn't get money.
when you purchase a book it's your own,(the author did get his money) you bought it and it's no problem to sell the book after a few years on ebay or so. or just give it away.
seems to me that this works with patterns as well.
(just don't sell copy's!)
so, just put it on a website and try to sell them.
if this wont work lots of people here would like to have them.
good luck!
