Are you a member of the https://www.facebook.com/groups/I1.Z140.YDNA.Project/ ? If not, I recommend it highly for anyone who has haplogroup I1 results. Join and ask the admin, William Hartley, for suggestions. He is probably in the top five experts for our haplogroup.
Agree with John. You would probably need to do more testing and William can look up your results with your permission and make recommendations. There is also this group: https://www.facebook.com/groups/Z138Project/
Pamela Sherren is already on My Heritage. She is the woman looking for Y-DNA I-M253. Her brother tested Y-DNA I-M253. Pamela's father was named Dirk Willem Stokes, born 1910 in Kenhardt. The gossip story is that he was the child of a man in Namibia. Seeing that Germans have Y-DNA I-M253, it is possible. She will put the DNA into My Heritage.
I also send her the facebook link.
Pamela will continue with her search.