I hadn't heard of it. Thanks for bringing it into my limited field of view.
Just did a search, and read lots about it..........including a TW forum members discount on one of the threads. It still works too. So I just ordered one for $100 instead of the usual $130. If that can make long term improvements, then it is cheap. Keep us posted as to your progress if you have the inclination.
(3) PT57A LM's, MG PT57A. 56/54lbs VS/Silverstring