I just Googled "S&W 4056" and the very first result contained the following:

From Post #6: "Estimated that around 1100 were manufactured, mostly in the MSE10xx - MSE20xx range; but a VJA9576 serial number has been observed." That post also has a great chart of 3rd Gen info.

From Post #18: "For anyone that remains interested, the 4056 sold for $1,185" (That was in Jan 2016)