Yes, somewhat unusual displacement.
This 175 cc category is very rare nowdays - I saw C-motos with that displacement engine only on the vietnamese and turkish markets.
Also, I know that "Lifan" makes CG clones with displacements: 133 cc (bore x stroke - 56.6 x 52.9 mm), 160 cc (62 x 52.9 mm) and "votive" 175 cc (62 x 58 mm).
Which crankshaft and piston they used to get 169 cc - only God knows. Maybe 169 cc is just lapsus calami...
BTW, where they found that CG clone? Parent factory does not makes them.