In the pictures I don't see much rust on the barrel. ?? But the receiver looks kind of bad. The butt-stock, and fore-stock are not hard to get off, very simple and taking them off you will know how to put them back on. Nothing like putting the receiver back together. (although that's not so tough) As I recall, where the screws go are pretty much common sense. On a 94 I don't think mixing up screws is a problem. But, no, you don't
have to dismantle the receiver.
The advice to check out the magazine spring and tube is good. That kind of
needs to be done, considering the condition of the receiver. Taking off the fore stock will allow you to do that. Also, you will want to see if there is any rust under the barrel and fore-stock. With both stocks off you can really go to work with your steel wool and oil, and really hose down the internals of the receiver. Carb-cleaner might be a good start. In fact, you could sit the receiver in a bucket of whatever for a day or so.
Re-bluing would not make much sense. It's probably pitted enough that it would take some serious polishing to get it smooth enough to do that. And if the sintered steel turns purple in a hot-blue, no you probably don't want a purple gun.
The "aged" look you'll get after removing the rust won't be bad. Kind of "antiqued". It's not a bad look, and goes well on a Winchester. It will also naturally age, if it turns out a bit shiney at first, and turn a nice grey over the years.
The 94 on the bottom has a sintered steel receiver/post-64. (top rifle is a pre-64) It was not rusted, but the blue was mostly worn off, scratched, etc. I took steel wool and oil to it, then put on some cold blue, and then lightly rubbed that off with steel wool. It came out as kind of a "satin grey". I think it looks okay.