To give my children the freedom to explore their faith and beliefs without fear of retribution or exclusion, and to let them develop their full potential as free individuals is worth any monetary inheritance.
It's your decision, but I imagine the 71 year old will be around long enough for this to be a problem for the kids.
You need to make some hard choices. I fully agree that money doesn't make up for wasted lives. It also doesn't replace what you can allow your kids to do or prevent them from doing. The thing is, your wife is still in so there is no real hurry to yank the kids out and make trouble. You should, however, start teaching them that their future is their own and somehow teach them that WTS is total BS.
Start helping your wife as you start helping your kids. As far as you losing faith in the Bible, it may be your path. I know it was mine. Once I researched WTS, the Bible was next. I don't insist that others see it my way. But it does make it difficult to talk to my wife. She's not deep into WT doctrine, but she stays for a couple of reasons; she believes they have the basic truth from the Bible, she loves the social aspect of it and can't imagine giving that up.
You can do your best to make sure your children know different on both of those. I don't know about your wife. You must follow your path and not deny yourself on your spiritual journey. If you decide to reject the Bible, it is a matter of time before you reveal that to your wife and she might have a hard time listening to you. Again, it is your path. You must take it wherever it leads you. Encourage your loved ones to take theirs.
My copy of COMBATTING CULT MIND CONTROL, while it doesn't have any mention of JW's in it, has a single reference in the back for people looking for help that is for JW's. Take a black marker and just line through the reference. Then JW's are not in that book.