It’s not an msd distributor it’s a firecore distributor and it’s brand new, in phase, and curved.
There is no play at the shaft other then turning the rotor ccw which will Engage the advance springs and allow the rotor to come back a little bit.
I think you misunderstood, it's the wrong cap for the Multi-Strike MSD system. That's about the cheapest TYPE of cap money can buy, and even if it's working ok today, it's only a matter of time before it makes trouble.
And how did you prove it's correctly phased? That is a very difficult thing to do without sacrificing a second cap.