My undersatnding is that something has to happen, arrest, threat of suicide, hospitalization for alcohol poisoning etc. is there a lawyer involved with the will? Maybe you could buy one hour of time with an attorney, or go see the prosecutor.
Big thing, document everything dates times, statements, actions, I mean everything, go to the $ store and get those marbled composition books with the sewn in pages and never tear out a page, you want them to know you kept meticulous records and that you did not fudge anything, periodically make copies of the pages and place them in a safe deposit box.
Brother and other guy both sound spooky to me.
Take care,
Bill