Hi. I too am working on my geneology, and my mother is a Lerche. I have traced the Lerche side through the North east of England, and Charles is a name that pops up quite a bit, whether it be in brothers or uncles within the direct line.
I am not sure what detail you have on the origins of your grandfather (born in the UK etc, D.O.B), but if I can be of any assistance, then I am more than happy to help and share what little I know
Regards
Richard