This is an interesting club! The back of the head which bears Spalding's Kro-Flit logo is also stamped "Bobby Jones" and "Professional Golfers Assn, Custom Made."  Hickory shaft clubs marked with Jone's name or initials are quite rare, as is this club, which is far more rare than even the Stewart unauthorized "RTJ" stamped irons made by the famous St. Andrews Cleekmaker.

So why is this iron marked with both a Spalding Cleemark and a PGA logo?  According to Pete Georgiady in his book North American Club Makers, Spalding occasionally made clubs for the PGA:  "In the 1920s, the Professional Golfers Association of America acted as a buying cooperative for quality golf clubs.  To help PGA member club professionals with small shops earn better margins on the equipment they sold, the PGA made volume purchases from major club manufacturers to secure lower prices.... Starting about 1921, the PGA obtained a variety of models from Spalding and MacGregor all stamped with one of several PGA logos."   

So why is this club stamped "Bobby Jones"?  Jones hated the idea of endorsing clubs with his nickname "Bobby". He preferred using his full name, "Rob't T. Jones, Jr.", which is how all the clubs he endorsed for Spalding were marked. The fact that Spalding marked this iron "Bobby Jones" sets it apart from Spalding's signature "Rob't T. Jones Jr." clubs. The Jones name was a surefire seller back in the day. So by marking "Bobby Jones" on the back of this and any other PGA clubs, Spalding did not encroach on their "Rober't T. Jones, Jr." clubs yet a clear marketing connection was made, which is likely why this club is stamped "Bobby Jones".  However, because this is the only PGA "Bobby Jones" hickory shaft iron the auctioneer has seen, it would appear that very few sets of these were made (a 6-iron is nearly always part of a set).  It is quite likely that when Jones found out about the production of "Bobby Jones"-stamped clubs he asked Spalding to halt such production, and they would have surely obliged.

Speculating just a little more, the auctioneer knows of a set of PGA "Rob' T. Jones"-stamped irons made by Spalding with pyratone-coated steel shafts.  “Rob’t T. Jones Jr”  is marked on these clubs just like it is on the early Spalding-brand clubs.  Spalding apparently stopped using the Bobby Jones stamp found on the PGA wood-shafted Jones iron offered here before making the PGA steel shaft Jones iron set known to the auctioneer.

Any idea that this club was made for Jones personally is without merit. Jones would not have used a club bearing the name of another club seller when he worked for Spalding. Of course Spalding would not want that either. No matter the genesis of this iron, if you love Jones, this club bears his name and is an about as rare as they come and part of his story.

The back of this iron head is also marked "Pat'd Sept 13, 1927".  This acknowledges W.F. Reach's patent No. 1642462 assigned to Spalding, which covered constructing a set of irons of graduating lofts, whose blades all have the same vertical measurement from the ground to the top line of the blade (measuring perpendicular to the ground, not angled).