Numrich Gun Parts
You can find most of the parts at e-gunparts, to find them do a google search of "e-gunparts".
The Stevens Model 39A was produced between 1939 - 1947.
Do a google search for "e-gunparts", they will have most parts.
The Model 39A was only manufactured from 1938 to 1945. Value is from $25 for a parts-gun to $150 for one in excellent condition.
I can say that the Savage/Stevens No 39 was made from 1938-1945.I cannot say if the model 39A is the same or not.
It's a .410 bore shotgun
The Stevens Model 39A .410 shotgun was manufactured between 1939 and 1948. It was a popular single-shot shotgun produced by the J. Stevens Arms Company. The model is known for its simplicity and reliability, making it a favored choice for small game hunting and youth shooters.
This is a stevens model 39A. The stevens 59A, B and C all had the takedown screw in front of the trigger guard.
There is 1 on gunbroker.comStevens Mod 39A / 59 A,B,C .410 shotgun bolt Auction # 147552744
No way of knowing without you providing a serial number to find the year of production of your Marlin model 39A.
You can get parts directly from Marlin by calling 1-800-544-8892. this model was produced 1971-1973, all internal parts are same as the 39a, the 39d is basically a 20inch barreled pistol gripped 39a