Hi Dave,
I haven't really done anymore on my pulsejet - the whole welding thing has put me off a bit and I've been busy with other things. They are very appealing engines though, especially if you want to irritate your neighbours...
The engine that I am building is actually of my own design (well almost...). There is an excellent website that is all about pulsejet engines. On this site, you will find many downloadable plans for engines, as well as a pulsejet design program that is based in Excel (this is what I used to design my engine). All these plans are free and there are also forums where you will find many people to talk to that are actively building and running these engines. I found the people there very helpful - a bit like CNCZone, I guess.
The site can be found at:
http://www.pulse-jets.com/
The above site is definitely a good starting point if you are looking at building one or just want to know more about them.
I hope this helps.
Regards
Warren