The 1929 Franklin had a frozen piston. It seems a mouse had built a nest in the exhaust manifold where an exhaust valve was open. The moisture generated over time was enough to corrode the cylinder wall and piston.
Disassembly has also brought to light other issues such as loose babbitt on some of the main bearing caps.
Franklin 130 disassembly 
Franklin 130 oil distribution from pump 
Franklin 130 motor 
Missing/loose babbitt on main bearing caps