Good ID, Dan. I don't know the 400 series, but I do know my two 301s - one very well and one in the get acquainted stage.
Stitch124, you can still get a 301 for under $100 on ebay if you aren't fussy about color and if you are patient. If the Kenmore won't FMQ, you might want to consider it.
This one is buy now for $59.95
http://www.ebay.com/itm/VINTAGE-SING...#ht_841wt_1178
This one has the cradle that you can turn around and sell for at least $25.
http://www.ebay.com/itm/Nice-1951-Si...#ht_746wt_1178 Whoops, no cord with this one so that's another $15 ish.