Certainly what you have there is salvageable. If you are going to use it you don't have to strip off the good paint, just the rust. Obviously will look better if you take it all the way down. Faster method is a 4" grinder with knot wire brush, be careful as those things don't play (if they kick it can get bad fast) and they tend to throw wires into your clothes and sometimes yourself. You could take it to a sandblaster and have them take care of it for you. There are products you can buy that are rust converters, but you have to be real careful with that stuff and they are certainly not a magic bullet.
Here is a pic of one of my rust buckets. Long story short it sat outdoors for 60 years before I got it. We had it running and driving in about 8 or 9 months, life got in the way so painting may be a never happens thing. We did clean and paint most of the engine components along the way while it was apart.
Cleaning for painting is a mundane task. I don't really care if I ever paint anything again, just turning wrenches is good for me. To keep you encouraged, here is another pic of one of my toys. We wire brushed everything on it--took forever and a day. I used a rust converter on most everything.
Not trying to hijack your thread here, just saying been there done that, and questioned why the entire process, so know that you aren't alone.
