You do not give a date of birth so is this your Otto ? Middle name is Mcclelland

Ohio, County Births, 1841-2003

Name: Otto Mcclelland Grace
Event Type: Birth
Event Date: 07 Mar 1895
Event Place: Marion, Marion, Ohio
Gender: Male
Father's Name: M.C. Grace
Mother's Name: Mamie Hanver

Reference ID: v 2 p 158 , GS Film number: 384336 , Digital Folder Number: 004016645 , Image Number: 00280

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Ohio, County Marriages, 1789-1994

Name: Otto M. Grace
Event Type: Marriage
Event Date: 29 Jun 1913
Event Place: Marion, Ohio, United States
Age: 18
Birth Year (Estimated): 1895
Birthplace: Marion
Father's Name: George B. Grace
Mother's Name: Mamie R. Hauver
Spouse's Name: Estella M. Marshall
Spouse's Age: 18
Spouse's Birth Year (Estimated): 1895
Spouse's Birthplace: Gratiot Co., Mich.
Spouse's Father's Name: Jason S. Marshall
Spouse's Mother's Name: Margaret E. Gillon

Reference ID: p 452 , GS Film Number: 384247 , Digital Folder Number: 004016610 , Image Number: 00592

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Ohio, Death Index, 1908-1932, 1938-1944, and 1958-2007

Name: Otto M Grace
Event Type: Death
Event Date: 16 Feb 1977
Event Place: Ross County, Ross, Ohio, United States
Registration Place: Veterans Adm. Med. Ctr
Residence Place: Delaware, Delaware, Ohio, United States
Gender: Male
Age: 81
Marital Status: Married
Race: White
Birth Date: 1896
Autopsy Performed: Unknown
Certificate Number: 013606
Volume Number: 22790
Certifier's Role: Physician
Affiliate Line Number: 13606
Affiliate File Name: DEATHS77.DAT
Source Reference: Ohio Department of Health

Yes, this is the Otto M. Grace that I am looking for. He was my husband's father. I was wanting to know if after Otto divorced Estella if she remarried? If so, to whom, when and where? My husband was George Russell Grace and he passed away in Tulsa, Ok. and is buried at Robbins Cemetery in Coffeyville, Kansas. He passed away June 11, 1983 - at the age of 53. Do you know any other information about the family background?
Carol J Grace

Ohio, County Marriages, 1789-1994

Name: Otto M Grace
Titles and Terms: Mr
Event Type: Marriage
Event Date: 08 Aug 1941
Event Place: Marion, Ohio, United States
Age: 46
Birth Year (Estimated): 1895
Father's Name: Geo D Grace
Mother's Name: Mamie E Hauver
Spouse's Name: Anna M Au
Spouse's Titles and Terms: Mrs
Spouse's Age: 26
Spouse's Birth Year (Estimated): 1915
Spouse's Father's Name: Thomas Calhoon
Spouse's Mother's Name: Elsie Teeter

GS Film Number: 000384252 , Digital Folder Number: 004752453 , Image Number: 00304

On the actual marriage record it states both where previously married.

You can view the marriage record on FamilySearch.com for free

1940 United States Federal Census about Otto M Grace
Name: Otto M Grace
Age: 45
Estimated birth year: abt 1895
Gender: Male
Race: White
Birthplace: Ohio
Marital Status: Married
Relation to Head of House: Boarder
Home in 1940: Toledo, Lucas, Ohio
Street: Deal Street
Inferred Residence in 1935: Marion, Marian, Ohio
Residence in 1935: Marion, Marian, Ohio
Resident on farm in 1935: No
Sheet Number: 5A
Occupation: Door To Door Salesman
Attended School or College: No
Highest Grade Completed: Elementary school, 8th grade
Hours Worked Week Prior to Census: 50
Class of Worker: Wage or salary worker in private work
Weeks Worked in 1939: 34
Income: 540
Income Other Sources: No

Ollie Hutchinson 40

Otto M Grace 45
Anna M Grace 25
Lorence Grace 1

According to the above census it looks like the family were lodging with a Hutchinson family

United States Census, 1930

Name: Otto Grace
Event Type: Census
Event Year: 1930
Event Place: Savannah, Ashland, Ohio, United States
Gender: Male
Age: 35
Marital Status: Married
Race: White
Race (Original): White
Relationship to Head of Household: Head
Relationship to Head of Household (Original): Head
Birth Year (Estimated): 1895
Birthplace: Ohio
Father's Birthplace: Ohio
Mother's Birthplace: Ohio
Affiliate Film Number: 1749

Otto Grace Head M 35 Ohio
Estella Grace Wife F 34 Michigan
Robert Grace Son M 14 Ohio
Marietta Grace Daughter F 12 Ohio
James Grace Son M 8 Ohio
Richard Grace Son M 6 Ohio
Bonnie Grace Daughter F 3 Ohio
Joseph Grace Son M 1 Ohio

FamilySearch Center.

District: 0001 , Sheet Number and Letter: 3B , Household ID: 89 , Line Number: 76 , Affiliate Name: The U.S. National Archives and Records Administration (NARA) , Affiliate Publication Number: T626 , GS Film number: 2341483 , Digital Folder Number: 004638888 , Image Number: 00011

I assume your father George Russell Grace was born in 1930 after the 1930 census

1920 United States Federal Census about Otto M Drase
Name: Otto M Drase [Otto M Grace]
Age: 24
Birth Year: abt 1896
Birthplace: Ohio
Home in 1920: Marion Ward 2, Marion, Ohio
Race: White
Gender: Male
Relation to Head of House: Head
Marital Status: Married
Spouse's Name: Estella M Drase
Father's Birthplace: Ohio
Mother's Birthplace: Ohio

Otto M Drase 24
Estella M Drase 24
Rolbert Drase 4 [4 2/12]
Mary E Drase 2 [5 0/12]

1900 United States Federal Census
Name: Ottie M Grace
Age: 5
Birth Date: Mar 1895
Birthplace: Ohio
Home in 1900: Marion Ward 6, Marion, Ohio
Race: White
Gender: Male
Relation to Head of House: Son
Marital Status: Single
Father's Name: George B Grace
Father's Birthplace: Ohio
Mother's name: Mamie R Grace
Mother's Birthplace: Ohio

George B Grace 36
Mamie R Grace 25
Alva M Grace 7
Ottie M Grace 5
Louie N Grace 3
Bennie Grace 11/12

George Britton Mcclellan Grace
Ohio, Deaths, 1908-1953

Name: George Britton Mcclellan Grace
Event Type: Death
Event Date: 08 Mar 1946
Gender: Male
Age: 81
Race: White
Birth Date: 23 Mar 1864
Birthplace: Centerville, Ohio
Birth Year (Estimated): 1865
Father's Name: Josephus Grace
Mother's Name: Flavilla Edmondson
Spouse's Name: Mamie R. Hauver Grace

File Number: Certificate , GS Film number: 2372805 , Digital Folder Number: 004073026 , Image Number: 00017

This looks like Otto's fathers death. In which lpace otto's grandparents where Josephus Grace & Flavilla Edmondson.

I am not related to this family and live in the UK. What else are you looking for ?