The 175cc Villiers Super Sport was current from 1924-32. In it's day it was a very successful engine holding World Records and winning major races. It even powered an outright winner of the Durban/Jo'burg race. It is still an engine in demand.
As to value, that depends on where you live and the condition of the engine. A quick look at your photos shows this engine has no electrics, no carburettor and has a broken crankshaft. The latter is a major problem as the Super Sport had a drilled crankshaft using the Villiers Autolube system which is also missing. This particular crankshaft is much harder to find than the common petroil lubricated version. It does have an inlet manifold which is a minor plus if it isn't worn out. The photos don't really show the condition of the the remaining parts so its difficult to make any further comment.
Essentially you have the bare bones of a Super Sport, the crankcases, inlet manifold, cylinder, cylinder head and conrod, nothing else.
It certainly has a market but not for a great deal as basically you mainly have the easy to find bits, not the hard to find ones.
For further info can you provide the engine number?
Cheers,