I prefer the moniker 'flexible adjuster'.
When I get down into position, it is easy to fine adjust the scope into the position you require. With a right hand shooter, with the scope and stand on the left and the left hand set in the sling, it was always difficult to try to reach the old round headed adjuster, the flexible adjuster eliminates this problem.
Im surprised someone isnt turning them out by the bucket load. Just a word to the wise. Ive noticed that some of the original adjusting knobs, mainly on Tuckers stands, can have different threads. This could of course be due to someone re-tapping the hole to fit a different knob, if they have lost the original and decided to replace it with an easier to obtain thread. I think, from memory, that in Andrew Tucker stands, the thread was 'UNF'. This can easily be checked by taking the diameter of the threaded knob, and checking it against details of threads that can easily be found on a Google search. These details will give you 'Threads per inch' so using a rule, count the threads. This should correspond with the old known threads, BSF, BSW, UNF and UNC. Metric threads were not used in days of yore. As for the Freeland scope, being American, they are more than likely to be one of the first above four threads.
Jonty