I just came across this document in the Pension records for Poole Hall Pope... (see attached image). Notice who made the statement and signed his mark at the bottom of the document... Jacob Pope. Could this have been the Jacob Pope that I wrote about above?

Probably so. It was 1833, Poole Hall Pope was an old man (in his 80's according to other documents in his Pension file), and his nephew Jacob was vouching for him.