My Campbell hausfeld pump is very similar to yours however mine uses 1/2"" copper tubing from the pump to the tank , you may consider using 1/2" tubing , BTW great job on the rebuild.
The otc testers are rated for 130 amps however the tell you that for every 100 cca above a 500 cca battery add 0.1 vots to the display on the meter for every 100 cca below a 500 cca battery subtract 0.1 volts from the display. I use mine on 800 cca batteries with no problem !
if you know the system pressure you should go 1.5 times the working pressure and hold it at this pressure for approx 10 minutes, best with an inert gas such as Nitrogen , and use snoop or soapy water on all the joints a presence of bubbles would indicate leakage on the joint, hope this...