Need O ring help

contacted FX support a week ago. no answer, no surprise, EBR. however after 5 weeks in warranty repair my impact 25 (Annie) has broken again. I blew O-ring part # c39 19763 9x1.5 nbr 90. this is apparently the new platform impact it has serial # under trigger housing. I'm not blaming them, I think I may have overcharged the tank

I didn't try AOA knowing they are obviously covered up and under stress. I also need the Belleville rod. it has spiral and grooves in the side. part #C 34 19696

I see I can buy a complete rebuild kit from amazon and ebay. I need this rod , I have had regulator issues for some time.

looking for advise or if anyone has parts , I'll pay you , of course. any experience with the grooved rod. I would say that would give me uneven regulator service.
 
I chucked the rod in my mill .... drill press will do.... and delicately dressed it on a flat diamond stone, then fine stone, to a point where there was no mark on the end. Haven't had a bit of problem since. Mine had the typical divot in it, but straight from the factory. Make sure it is STRAIGHT in the chuck. NO wobble. Not sure if that will help you. Their orings are all 70 D that I've touched. Also, the one in the frame for the reg seemed to be undersized. I replaced it with one very slightly thicker and no leaks or reg drifting for quite a while now. 

Bob