Taken from Don Bunn's B-Series Truck book, there were 27 truck body models from 48 to 53, including Conventional Cab, COE's Panel's, Pick-ups, Power Wagons, Express, Platform & Stakes.
Production by calendar year were:
1948 - 172,020
1949 - 151,513
1950 - 125,773
1951 - 169,000
1952 - 162,871
1953 - 105,248
Many of these were in military pools, corporate fleet trucks for industry and farm production while I believe F & C were more targeted for the mainstream consumer supported by heavy advertising, marketing and as you mentioned, more dealerships. Of the million or so Pilot-House Series and Power Wagons produced in this period I think our Forum and the PW club probably represent a high percentage of the survivors, I would estimate a wild guess of under 2500.