Dear Tom,
I suggest you contact Jeff Ellis,
http://www.antiqueclubs.com/, and / or Chuck Furjanic,
http://www.golfforallages.com/. These two appear to be the leading authorities on collecting golf clubs.
You probably also should know that there is a catalogue of Locke's memorabilia that was sold at auction. Bobby Locke died in 1987. Six years later, his wife and daughter, under pressure of necessitous circumstances related to the turmoil in SA, sold a great many personal memorabilia items through Christie's in July 1993. There is still a catalog available, if that interests you.
Christie's Catalogue of Bobby Locke Memorabilia Auction, July 1993
http://www.antiquegolfscotland.com/antiquegolf/shop/index.php3?productid=1323
I hope this helps. Let me know what you find out.
Cheers!
Geoff Mangum
Putting Theorist and Instructor
PuttingZone
http://puttingzone.com
Golf's most advanced putting instruction.