19th April update.  I am pleased to say that today I have adapted the Morley to perform just as well as the Gaugemaster. This is done at the cost of maximum speed (just a little) as the output was higher. I am still finalizing components and then will consider making a 'how to video' but experience and understanding in transistor isolation, component identification and a means of testing capacitors to get a balanced pair will be essential.  This of course will totally invalidate your guarantee