Farmstitcher, I have a reg. 306 machine and it takes the 206X13 needle which you can still find. This machine will also use a double needle. I am going to list some of the features of my 306 and maybe it will be the same as what you are looking at.
Full vision bobbin case,calibrated tension for accurate adjustment,reversible feed,calibrated stitch regulator,smooth seamless throat plates,positive feed for handling all types of fabrics,oneway needle clamp makes it almost impossible to place needle in clamp incorrectly,takes the fashion discs for making decorative stitches. Hope this helps you in your decision. I like mine but don't know if I want to treadle it also have another one DH is going to put a hand crank on it. Here's a picture of mine.
Singer 306
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