Hello Chris,
I'm wondering if you have come across the Penvose spelling of the name? I at first believed the name was changed when the family immigrated to the US, but have been in touch with one line of the family, now living in Barnsley, Yorkshire, and they also use the Penvose spelling. The earliest ancestor I've been able to locate is John Penvose born circa 1821 in St. Austell. He married Jane Blewett in Tywardreath in 1847, and died there in what I assume was a mining accident, in 1866. All his children, except Edward Penvose, immigrated to the US in the early to mid 1870's, settling in Tioga Co., PA then later in Clearfield Co., PA.
The spelling variation has been a mystery to me for years, so if you have any thoughts on this subject, I'd appreciate hearing from you!
Thank you, Dorothy