I found this website, or person that says they have a stock for it. Are you in need of one due to damage or just wanting a synthetic? If you're just in need of a replacement stock try this place? Scroll down the page and find your model. It was made in the 50s/60s and not a highly sought after model. Unless for collecting purposes. i could be wrong.
Usually when you do a search and no auctions or not many sites other then informational pop up, not a good outlook for parts. I highly doubt you'll find a stock in synthetic. Might find a replacement original or NOS stock though?
Mossberg Bolt Action Shotgun Parts
G-Meister