Another option is restore the Dyna MK IIIs to their original schematic and specifications. I did that with my MK IIIs. All new resistors and caps but stock values. With the new higher quality parts it has several advantages. One of the main ones is that it will match the manual and published schematic drawings. I have owned my pair for 46 years and this is the second complete rebuild. I like this rebuild better than the original kit build or the 1990 rebuild. All parts are readily available. You can see details of mine at
https://dynacotubeaudio.forumotion.com/t3641-kiwame-rebuild-of-my-mk-iiis
If you decide to go this route send me a note and we can discuss the many options.
If you decide to go this route send me a note and we can discuss the many options.