rm18382:
Nice to see the Crown Dependencies didn't get disarmed when Britain decided it couldn't trust its people.
Your club has inherited a Model 36 Chiefs Special manufactured in 1975 or 1976. Serial range for those years was J250001 to J370000, so 1973 seems likely.
llwsgn:
Your .38 Military & Police (Post War) was manufactured in the period 1948 to 1951. Serial range for those years was C1 to C223998, I'm going to guesstimate early 1950.
Olympus:
Your Model 66 was manufactured in 1975. Unfortunatrly it doesn't list an MPD marked gun in the various special runs for police departments. A S&W factory letter would probably sort that out for you, but it costs $50. You'll have to decide whether satisfying your curiosity is worth that much.
h204ever:
The Model 29-8 .44 Magnum Mountain gun was a stocking dealer special in 2003. Most guns shipped that year had a serial number starting with C, so your gun may be a more recent run - the Standard Catalog of S&W was published in 2006 and does not list the most recent serial ranges or special runs.
As your gun is quite recent a call to S&W will clarify that for you, it should be on their computers rather than in old paper records. They should also be able to supply you with a key for the internal lock.