Hello Klaus,
Thanks for looking up the Sandstedt "Hinrich" Oldenbüttel and your confirmation that he could well be my "Henry" Oldenbüttel. I think this is a pretty good circumstantual fit, and probably the best "evidence" we are likely to find at this distance in time. It is certainly good to get independant confirmation of my own research.
Following Hinrich's family, I get back to a Gerd Oldenbüttel b. 1707 d. 1766 Wulsbüttel (although many details are still missing).
Thanks very much for your help and interest.
Regards
Max