No, that's fine ! In some ways just to know that someone else can't come up with the answers either, is reassuring for me. I have been gnawing away at this for nearly 20 years, so to imagine it all to be solved like magic, in a flash, would be foolish.
There will come a breakthrough eventually, as more and more records are made available online, I suppose. In the meantime I'll have to attempt to crack some of the other sticking points in my family !
I will follow up that last bit of info you sent, though, and see what else I can find regarding that name. [ There were Parlby's in that part of Devon, but I haven't found them to be connected so far. They seemed to have been far more aristocratic !]
Thanks for your contributions.