I would *definitely* overhaul the 401. I have two of them and have given away a third. It's the machine I learned to sew on and if you're not feeding it a steady diet of canvas and jeans, it will be a wonderful machine to learn on.
You can buy additional attachments and cams (although I don't think you really need the cams - most of my sewing is straight-stitching with the occasional blind-hem stitch - I'm pretty sure that's built in to the 401) If you look on eBay, pretty full sets of attachments and cams for the Touch & Sew machines go for a song. The white cams and the chain-stitcher sets from those machines won't work on your 401, but the black cams and the other slant-shank attachments will be just fine. Usually a lot less expensive than the sets made and marketed for the 401, too.
You're not going to be able to buy as sturdily built and versatile machine as the 401 for what it's going to cost you to refurbish it.
And you might save even that, if you like to tinker around with machinery (which I absolutely love as much as I love sewing! LOL! ) You might find that it's fun for you, too.
Have fun with your old gal - nobody makes 'em with that quality any more.