According to death records at ancestry.com he died in a nursing home in Hocking County but because he was a veteran his body was handled by the VA Hospital Medical Center in Dayton, OH and he's buried in the Dayton National Cemetery:

Name: Nikolai Sinelnikow
Birth Date: 1 Jan 1926
Birth Country: Remainder of World
Gender: Male
Race: White
Hispanic Origin: Not Hispanic (Latino)
Residence County: Hocking
Residence State: Ohio
Residence Country: United States
Death Date: 26 May 1992
Death Time: 7:30 AM
Hospital of Death: Long-Term Care Facilities
County of Death: Hocking
Certificate: 035268
Age at Death: 66
Certifier: Physician
Referred to Coroner: No
Autopsy: No
Filing Date: 28 May 1992
Hospital Status: Other/Nursing Home
Injury in Ohio: Yes
Type Place of Injury: Unspecified Place
Social Security Number: 216-38-6625
Marital Status: Never Married
Education: 6
Industry of Decedent: Military
Occupation of Decedent: Cooks, except short order
Primary Registration District: 3700


Name: Nickolai Sinelnikow
Service Info.: SPEC5 US ARMY VIETNAM
Birth Date: 1 Jan 1926
Death Date: 26 May 1992
Service Start Date: 21 Nov 1951
Interment Date: 28 May 1992
Cemetery: Dayton National Cemetery
Cemetery Address: VA Medical Center 4100 West Third Street Dayton, OH 45428
Buried At: Section 25 Site 1051

I would contact the VA Medical Center or the Dayton National Cemetery for more information:

http://www.cem.va.gov/CEMs/nchp/dayton.asp

He's listed in the burial records at the cemetery:

www.interment.net/data/us/oh/montgomery/daynat/