IMHO, I think that this is the original Stevens barrel, lined and set back several inches and a new forend. The rifle is most likely a model 47.
I also think that this is the original butt stock and the carving is more likely a tracing with a combination of light carving/stamping and wood burning. The deer design I have seen before. If memory serves me right, Brownell's had stuff like this in their catalog in the 1970's.
You can really see the effects of the hot blue turning the lever casting purple.
That being said, I would still buy it as a parts gun if it was priced right. I've always been a sucker for every "silk purse" hiding in that "sow's ear".