DUI_Diver,
The only "special" tool you need to service a Zeagle diaphragm regulator is a pin spanner wrench:
http://www.zeagleexpress.com/gear/REGULATORS/Service Kits and Parts.html
You can also buy the service kits from the site listed above.
For the very 1st Zeagle reg I serviced, I actually modified a bicycle spanner wrench I had laying around. I subsequently bought a set of pin spanner wrenchs from Scuba Tools; they do work better than my homemade one
You'll need a good set of hex wrenches, open end wrenches; brass o-ring picks, IP gauge.... the initial cost
will probably be a bit more than a typical service costs at the LDS, but the tools are a 1-time expense.
Good quality tools and gauges are available here:
Scuba Tools
I have a PDF service manual for the Zeagle Flathead, DS-IV and 50D.... I've had it so long I cannot remember where I downloaded from, but if you need it, send me a PM and I'll e-mail it to you.
I own 2 Zeagle Flathead VI's, and have to say that a talented child could service them. They were designed with ease-of-service in mind, and are super easy to rebuild and tune. I'd say they are
easier to repair than a leaking toilet (or at least more fun
).
Best wishes.