Perhaps this could give you a back door in. From the marriage directory I found a possible sister to Henry Merritt Bostwick provided his parents are Merritt and Diantha Nash. Merritt has a probate file 5278 dated Jan. 15, 1894, which is available thru the Rock Co. Historical Society. Merritt and Diantha had a daughter Francis P who married Henry J Beckwith. Francis shows a possible probate file of 17364 dated Jan 20 1926. If this matches up I could dig further into Francis and look up Diantha's death record.