That looks great!
Even though it is rated at 5 watts, tube amps are generally more efficient (and normally require more efficient speakers), and that's probably why it feels so loud. I love tubes, I fell in love with them listening to a tube radio in Mexico when I was a little kid.
I'm currently rebuilding said radio (it's a desk top unit) that was my grandfathers. I also plan on building the following:
http://www.s5electronics.com/l16stereo.html
(16 watt tube amp, but modified with everything except the tube sockets and transistors mounted upside down, allowing the tubes to stick out the farthest through the enclosure like your tube amp).
It's going to need one of these:
http://www.s5electronics.com/lpre.html
So that I can use my vintage turntables (old directdrive Kenwood and a fully programmable Fischer).
And I'm thinking about one of these to complete the package:
http://www.s5electronics.com/ltone.html
Their old 8W unit gets amazing reviews, and considering the price of new, and even vintage units, I rather build my own.
Now to get the money to do it...
Any sound samples?
Mario