I ripped the threads out of an FSA drive side carbon crank trying to remove it with a washer still in it a few years back. Not my best moment, but I swear I checked and saw no washer.

Anyway, I called FSA to see if they had any new old ones left, since the style I had was discontinued. I told the support guy what happened and low and behold, he sent me a new arm FREE. Great customer service.

I suggest you give them a call and see if they have any, and maybe they will send you one. I think I had to return the one I damaged.

Otherwise, you have nothing to lose by straigtening the one you have. If your other timing ring is straight, perhaps you can use it as a guide to align the bent spider.