Hello folks,
Since I'm a repairman and my main job is keeping guitars in good working order, I try to be pragmatic when these kind of questions present themselves. However, I'm also a historian and I like to see guitars in their original condition and we are lucky that so many 'drop in' aftermarket parts are available these days.
In this case we are looking at a set of Japanese tuners that was only used by Guild for a short period of time and to the best of my knowledge there is no aftermarket tuner with a similar footprint (and of reasonable quality) available to replace the ones on this D-40.
Since this guitar is from 1967 (and not from 1969) I was thinking about using another set of tuners that Guild used for a couple of years before the guitar under discussion was made. They were made by Van Gent and they are really good quality tuners that will probably come close to covering the footprint of the original tuners. I believe it should be possible to find a good working set that would have been factory correct if the guitar had been made a year before that.
This is what these tuners on a D-40 from 1966 would look like:
Sincerely,
Hans Moust
www.guitarsgalore.nl