There were very few shipped in 1946, like maybe 50 guns between K101 and K150 at the highest. We then know that guns up about K18,000 were 1948 guns. Your gun is about 1/3rd of the way along, if you assume (and thats a huge assumption) gun production was level. From that interpolation, you might conclude that April or May was a fair guess.
If you really want to know more closely, you'll need to send the $30 to the factory and get a factory letter. It'll also tell you who it was shipped to originally.