Like I said, I usually refer to them as Vert Reg and Front reg or LPR, when referring to Cockers...thing about Cockers, is they generally have 3 regs, and most other gats only have 2!!
Anyway...I dont see what is so difficult...the LPR if in the Fore Grip on your Angel...you have a link to the WDP site...I looked at the manuals for A4 and Speed...both quoted the pressure mentioned above..go have a look...Just make sure, that you run 450 PSI from the reg on the bottle, whether that is from and Adjustable system, or froma 450PSI Preset system.