I noted the model number and did a little research on the thing.
There's not a huge amount of information readily available, but apparently the Kenmore 1430 Zig Zag was a pretty popular model somewhere in the vicinity of 1972 and is an all-metal workhorse that can sew easily through several layers of denim and even leather (demonstrated here on YouTube) and has "6 quarters" of room underneath the presser foot -- great for quilting.
Just the same, the machine I found was not in working condition and cost a fair amount of money, so I passed on it. But it stuck in my mind, and I visit that thrift store several times a week. Yesterday when I was paying for my latest finds, I looked up at the marquee where they advertise the day's sale tag color -- blue. Of course, nothing I was buying had a blue tag. But. The vintage Kenmore sported a blue sticker. I asked the saleslady if that counted, and she gave me the nod. Half of a fair amount of money seemed reasonable to me -- if the thing could not be fixed I could sell it for parts -- so I nodded and she rang it up.
Now I am totally beside myself. I rushed the machine to my favorite fabric store in downtown Burlington -- they have a man there who comes in to do repairs, and he'll be in on Tuesday. I can't wait to hear from him! In the meantime, I have joined the Kenmore Vintage Sewing Machine group on Yahoo Groups (yes, of course there is one -- search for "vintagekenmoressew" if you are so inclined) and am combing Ebay for parts and accessories. What fun!