The only inscription I can find in the Overholt Cemetery listings (in Humberstone Twp, now Port Colborne ) is:
ECKER/Cameron/died Feb 25,1920/Aged 36 years/ Margaret PAGE/his wife/died Feb17,1918/Aged 31 years.
Nothing listed as ACKER.
After much searching, I did notice that there is an Overholt Family cemetery in Thorold. I'm not familiar with this area but if you want I can look into it further and see if I can find an address.