I also have a 1949 336.
I replaced all of the wood on mine and completely reblued it.
Western Gun Parts had a complete factory stock. I had to phone in and provide the serial number and explain that it was a 1949 version of the 336.
It looked to be have been taken off of a new rifle as there were some markings on the butt from the mounting screw.
It did require very minor fitting of the fore stock and I fitted new barel bands and screws at that time.
I also installed a Williams rear peep sight and a Williams front sight that matched the height.
Expensive, yes, worth it, yes.