Holley 600 carb help

Help please . . . I've got a 600 Holley 1850-4 / 4160 on my 383. I have no history on this car or engine. I have been fortunate to have got it running without too much grief, it runs good, but continue to find issues that I am glad to have you guys for.

I had a gas leak at the accelerator pump. I pulled the pump and didn't see any damage to the diaphragm, so I cleaned it up and reassembled. It still leaked.

The engine also has a definite hesitation and falls on its face when you give her hell, which I am wondering is also accelerator pump related. If you baby the throttle, you can accelerate steadily and hear the secondaries kick in. The timing is around 10 (old school with a timing light), new plugs, new wires. It idles good, but even when you aggresively open the throttle at the carb, it definitely will hesitate.

After going to the Holley site, I purchased a replacement diaphragm 135-5, 30cc, which I believed to be the stock/standard diaphragm.
As you see in the pics, the diaphragm I purchased is not the same as the one that was originally on the carb. The one on the left is the one I found on the carb, the one on the right is the 135-5 I bought. So I am guessing my original one is not the stock/standard diaphragm. Which one is correct?

The accelerator pump cam is orange in color and is screwed in at the #1 position. The pump nozzle is #25. What's your guys opinion, should I change the cam and nozzle to help with the hesitation?

Any ideas / suggestions to help remedy my situation or improve it? I'm also thinking that if I just replace the diaphragm, I may stop the leak, but not do anything about the hesitation..

Thanks guys . . . . Rog