Well not to shabby for your first, good job. Looks like your gonna need to do some painting on him behind the neck and also looks like the first picture has some slippage about a 3rd of the way down from the skin sticking up unless I'm seeing things....if so that also will need to be removed and painted. The tail needs some work if its not dry, you will see how the rattle is not flowing off the tail line evenly, if you have caulk or clay in there you should be able to work it back over if its not dry. Your eye is to round and almost too Gold for the snake, here is a reference for you to compare, take a look at the eye shape.

I would like to see the head much closer and both sides and frontal view for symmetry because the head on a snake is the crux for the most part. I can see from the picture you have some lip line issues and nasal pits almost are looking to low as if the skin is hanging down to far but with out better pictures its a best guess.
You said your thought you read the tape wrong BUT trust me you were correct but the snake stretched, that's just what they do when they are skinned and fleshed. A pain to work with but that's snake taxidermy
All in all a great start for your first.....
