I have two of the four knobs required for the NE model 851A that is currently undergoing restoration…I have the tuning and volume knobs I believe. The other two knobs would be slightly different since they are for Tone/on off and Band selection…I have enclosed some photos of the knobs I have ( K-5176-1 ) which show the basic dimensions etc. If anyone has the other two knobs for this radio ( K-5955-2 and K-5955-1 ) let me know…or if you have a set of four that are roughly the same size let me know as well…