I have information on a Dina Hollmann which immigrated to Nebraska. She was married to an Othling who also comes from Diepholz.
I think there are three parishes in Diepholz.
Please reply and tell me your mail so I can send you a mail to discuss this further. I don't have many information my self but know where you can get them or I am eventually able to get them for you .I am living about 1 hour drive from Diepholz.