I found a second-hand Fender Squier SD3 Nat on a local buy-and-sell Facebook page for £25.
The first task was to remove the strings and tuners.
Next I had to work out how to add two more tuners to allow for four pairs of strings.
I had seen online a couple of conversions where people had added two extra machine heads at the top or in the centre of the headstock.
I decided that I wanted the headstock to look authentic so I used a design program on my computer to create a one-to-one scale drawing of it.
But before that I needed to buy eight tuners that would fit the headstock. I got these online and created accurate drawings of them to position them on the headstock with the bottom two tuner holes remaining in the same position.
I plugged the top four holes with dowel and used a belt sander to smooth of the front and back of the headstock.
I used a printout from the one-to-one drawing to make a template to mark out the position of the tuner holes.
Having drilled out the tuner holes, I varnished the headstock with a few coats of mahogany varnish. See from the photograph where the end grain of dowel plugs have taken up more of the stain at the edges.
Without the skills or inclination to replace the bridge I needed to fill the existing six plug holes and drill eight new ones.
I plugged the holes with dowel, inset 3mm below the surface of the bridge and filled with superglue mixed with sawdust.
I masked out bridge and sanded it down before spraying it with black paint.
I used a one-to-one drawing in my design program to experiment with string positions and came up with a string configuration that seemed to work. This gave me a template to position the string pin-holes.
Bridge pins are tapered so I experimented with scrap wood to get the correct drill size to accommodate them. I drilled the holes in the bridge using the template as a guide.
Similarly, I used the one-to-one drawing to work out where to position the slots on the saddle and the nut. There are quite a few tutorials on YouTube which show you how to shape saddles and nuts which are well worth consulting. I bought blank bone saddles and nuts online, along with some fine files, and shaped them to fit my design.
See the Tanglewood Nashville conversion for dimension diagrams of the saddle and nut
Getting the correct height for the nut and saddle is a matter of trial and error. Basically you have to string the instrument and tune it up then work on a string at a time to achieve a good playing action. I used pieces of cut up credit card to protect the neck and bridge while I was sanding.
I used the original saddle as a pattern to get a compensated shape to the saddle.
I was pleased with the finished Squier guizouki. After much trial and error I had a reasonable instrument.
However, since I began with a cheap laminate guitar I had to accept that the sound quality was not going to be that great.