My condolences on your loss. Along with the loss of losing a loved one. It is also the realization of losing a link to the past. Everytime that I lose someone I grieve for them, but I also grieve for losing my living attachment to those special times in the past. Somehow the Depression and WWII along with previous generations are removed further from my life. My history is diminished with each passing.
Your grandfather had a long industrious life and he is now reaping his rewards in the hereafter. It is those that he has left behind that need confort and solace. For that I will say a prayer asking God to bless you with His peace and love.