Its a spruce top tone wood - yew back and sides. No idea what yew would sound like as a tone wood on the top, but I have seen good words said about it.
The sides are one solid piece of yew the colour change being heartwood through to sap wood.
I like the tonal variations in the Yew, and what a sexy body shape too!
The yew trees I've sheen in Texas look more like big shrubs. I guess they must have bigger cousins in order to generate wood big enough for that two piece back.
That is a really cool look to the sides. At first I thought it must be joined, like "bottom half yew/top half spruce" - but even cooler that it is one piece. I'm also looking forward to hearing it in action.
Yes Rosewood fretboard. He works alongside Pete Howlett; they are currently developing a Tenor Cutaway together which looks to be really special. Tom also has his own website and Facebook page: https://www.ziegenspeck-ukulele.de/english/
I'm really happy to finally see one of Tom Ziegenspeck's beautiful instruments here on UU! Tom seems to be a very talented builder of very beautiful custom 'ukuleles here in Germany who certainly deserves more attention. Thanks a lot for sharing!