A good online resource for Cleveland history is the Cleveland Necrology File at www.cpl.org.
Is this your Kaplan?:
Id#: 0568130 Name: Kaplan, Celia Date: Mar 17 1967 Source: Plain Dealer;Cleveland Necrology File, Reel #122. Notes: Kaplan. Celia Kaplan, wife of the late Abraham, devoted mother of Daniel, Saul of Los Angeles, Mrs. Bessie Aronovitz of New York, Mrs. Rose Pressman, Mrs. Ida Selko of Los Angeles and Mrs. Jennie Kohen, dearest sister of Morris Kaplan, Ben Kaplan of San. Francisco, Sam Kaplan (deceased), Henie Alpern (deceased), Annie Abras) (deceased) and Jake Kaplan (deceased), loving grandmother and great-grandmother. Services at Berkowitz-Kumin Inc. Memorial Chapel, 1985 S. Taylor Rd., Cleveland Heights. Friday, March 17, at 11 a.m. Interment Warrensville Cemetery. Family will receive friends at the residence of Mr. and Mrs. Hyman Pressman, 2299 Clendon Rd., University Heights.
I'm also researching Cleveland Kaplans, although I think these are different Kaplan lines.