Family #23 in the 1767 Grimm census.
1767 Grimm Census 
Regarding the surname Heilm, This appears to be one case where a surname has been misspelled. There were no other Heilms in any Grimm census records, nor any in the 1798 Census for the Volga German Colonies. A search of German birth records shows the most likely spelling to be Helm, although it could also be Heil. In the Volga German there were Heim, Helm, and Hein surnames. I haven't had a chance to go through all the possibilities to look for a match, but I do know that none lived in Grimm, where his wife's family lived.
The couple does not appear in the 1798 Grimm census, and most likely moved to another colony.
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