Thanks for the update

Not found a father & son named William with occupation mason nor a marriage

1835 William son of William & Elizabeth no occupation for father
1837 William Henry son of William & Fanny father farmer
1840 William Henry son of William & Grace father labourer
Have a check on Cornwall OPC
https://www.cornwall-opc-database.org/search-database/ - have listed a few names above
Edit to add
birth year which was implied but not verified is after July 24 of 1837.
Certificate says nearly 75 in 1912.
The only birth showing on GRO indexes for a William Pengelly (included similar sounding variations for surname) in Cornwall district was registered in Dec 1838 Penzance
mmn Richards, there are a number of others after that year some with middle name Henry from 1840 onwards