Thanks Starlady.
One of the reasons I find it hard to let go the issue of his not having a will (& please, don't get me wrong, I'm not nagging him every time we speak on the phone - those conversations are only ever face-to-face) is because following our mother's very sudden death 30 years ago, we went through all the legal rigmarole at that time.
I recall him saying that he wouldn't want his kids to have to do what we did - but it's possible he's forgotten - so, I agree that the issue is mine. Even though we are siblings, we don't really know each other well & have totally different outlooks on life. There's a 15 year gap between us, we have totally different memories of our parents, but we get on like a house on fire!
Thanks for your time. 