From
http://www.vwtype3.org/info-serial-numbers, my best guess this is a Beetle, not a type 3 from the chassis. So look up Google's favorite Beetle chassis/engine numbers:
http://www.bug-bits.freeserve.co.uk/bugbits/data.htm
4 615 422 - built somewhere between April 1962 and May 1962 (probably on the first week of April, most likely the 3rd to 5th of April). This page has the following to say about the car:
http://www.together.net/~rhill/years2.htm
1962 (1 Aug 61 to 31 July 62)
Chassis 4,010,995 - 4,846,835
Engine 3,924,023 - 3,924,914
5,958,948 - 6,935,203
"Fuel gauge replaces reserve tap. Tail light 鈥榞lass' now plastic. Spring balance to front hood. Sliding covers on heater outlets. Progressive valve springs. Anchor points for seat belts. Stronger clutch springs. Windshield washer uses spare tire for air pressure. Last year of semaphores on domestic models."
T 0 925 265 - single port carbie, 1600 cc built somewhere between August 1965 and July 1973. Probably towards the end of the production run. It's possibly a type 3 engine, but a really late one!
Do you want to take some pics for people to have a look at it?