Hi Richard,
I realized that a Charles Oesterlein was a pork butcher in Osset, Yorkshire. He originated from Schwöllbronn, a village near Öhringen. It might be that this Oesterlein was related to Frederich August Louis Schoch, possibly his uncle and that your grandfather had someone there who he could go to. How old was your grandfather when he emigrated, have you got a birthdate?
I know a person who sometimes visits the Öhringen church archive. I asked him to look for the Österleins and Schochs when he will be there again. He promised to do so, but said that he will only be there again in June or July. But anyway, I think this can bring quicker and better information than you had got during the last few years.
Best wishes
Histres