[Boatanchors] 51J-4 with S-line knobs

[Rick Poole]

What can you all tell me about the Collins 51J-4 that came with 
S-line knobs? Some research indicates that only the latest 51J-4s 
were so equipped, and the labeling on the front panel also uses a 
slightly different font from the previous models. So are these 
considered more or less desirable than the ones with the Dekaware 
knobs? Were they part of some special contract?

Rick WA1RKT