I've found that on FamilySearch, the entry for Johann's marriage in the Germany, Bavaria, Nuremberg Civil Registration, 1803-1886 database has him listed as Johann Schmidt [Grimm, Johann] and there is a death for Johann Schmidt [Grimm, Johann] 28 Mar 1883. But I can't see any mention of the name Grimm on the copy of the marriage record which I have. On FamilySearch it says to view the image by clicking through to Stadtarchiv Nürnberg, but when I click on "Visit Partner Site", it takes me to the Stadtarchiv Nürnberg homepage and there doesn't seem to be anything to click on there to view civil registration records.
Also, daughter Anna's marriage record from 16 May 1883 says that her father lives in Nurnberg which suggests the Mar 1883 death is not him. It says the groom's father is deceased but not that hers is. Actually, he was a witness! So I wonder what the name Grimm has to do with him?