Is there an online data-base where I can lookup matching numbers for my '39?

You may try these, but there must be others as well on the net.

http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/1935to1942models.html

http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/cast.html

http://chevy.tocmp.com/chevyresto/3905.htm

Good luck!
http://chevy.tocmp.com/chevyresto/3913.htm

Depends what you mean by matching numbers.The engine casting number can be verified that its a 1939 block,etc....

If your 39 is Canadian the engine serial number will be on the trim/serial number plate attached to the firewall. The engine number is by the fuel pump......Joe

jiaccino, My 39 is 'merican.

Chev Nut, What exactly is a "numbers" car?

A matching numbers car would be a car with all the major castings have the correct casting numbers for that year.Also the date code that the casting was made should agree with the date the car was assembled.
As an example if the car was assembled on May 15th the casting dates would usually be from April of that year, give or take a little.
The Vintage Chevrolet Club does not really consider casting dates.More of a fun club than a high buck car club.The engine casting number could be checked to verify year but dates by month are not checked.Also a 1939 Chevrolet is not a big-buck car-say as a 1957 could be.(I own a 1939).Most are satisified if the engine is of the correct year and it has the original type carburetor,etc.I really wouldn't worry about it being a numbers matching car.
If you post the serial number (on side of cowl under hood) and the Fisher Body numbers (plate of front of firewall), and the engine number stamped into the ledge behind the distributor, we could give you some info. about the car.

Thanks Chevgene, I am not really worried about matching numbers , just curious what it meant. I know the car is not a high dollar car, but I want to preserve a piece of history and I love the suicide doors