Quite a few of us have. You might want to spend a few minutes browing "the rig" threads. You'll find tons of things to look out for and hints and tips and tricks.
The important thing with these things is to take your time. And if you are not sure about something DONT DO IT!
There are lethal voltages hanging around inside tube amps. If you are not sure about something don't go poking around. Ask a question here or visit a competant tech.
If you take your time and ask lots of questions you'll learn a lot, have agreat time doing the build and get a cool little amp out of it at the end
I did. It's a bit like building warmoths, once you've done one, you'll want another and another and so on.
Good luck and keep us posted.