Hi!
I take it you didn't find these guys in the WWII DRCs?
Did Leroy's wife's obit mention place of interment? If so perhaps the gravestone or the cemetery records might lead you to Leroy. If her obit did not mention the cemetery, did it mention the funeral home?
Similarly for Fred... Perhaps Margaret's DC will prove helpful in tracking down cemetery info. (Or the records of the sons?) I don't know if you plan to order from the local municipality or the state, but you do have both options, as you probably know, as deaths were registered with the local clerk and then sent to Albany. (However, MCs were filed with the county clerk until 1935.)
Sometimes it helps to check separately with both the local clerk and the state.
Port Chester Clerk:
http://www.portchesterny.com/page.cfm?pageID=23There's also the option to cold-call area cemeteries.
If Fred really did leave the family, Margaret may have been listed as a widow even if that wasn't true. I guess it wasn't common, but I mention it because one of my guys was separated from his wife and living in Brooklyn. She was living in Manhattan and listed as widowed. They later got back together for a little bit, and I've wondered what the neighbors thought!
OTOH, I have another guy who was deceased several years, then reappears in the directory along with his wife, who was remarried by that time. Go figure!
Another thing...I'm not sure exactly when the NYS Index switched to soundex. However, some of the earlier years were not in soundex, making it more difficult to search if the name was spelled incorrectly. There's a good chance the library could have missed him if this was the case. Even with soundex, there could be entirely different first letters in the index (wrong interpretation of the handwriting). The index is available to the public in 9 libraries throughout the state, although it doesn't appear to be in Westchester. The nearest would be the National Archives in Manhattan. (It's in NYC, Buffalo, Elmira, Glens Falls, Albany, Patchogue, Rochester, Syracuse, Watertown.)
Wishing You Luck!
Cheryl