Well, just found this via UKGSer and have ordered after reading Steptoe's glowing testimonial.
I've only just started doing this job myself and built a basic manometer which I was very pleased with, given the results I got. However, it's not a particularly convenient thing to keep/store and I think the harmoniser will be a good step up as I learn to do this properly.
Look forward to receiving it and playing.
Oh yeah, new tools