The backglass animation balls are near impossible to find (sorry Mark).

I was going to buy the one Retropin ended up with and sussed out all the 'big guns' for old EM parts in the US and had no luck.

Still I have seen the backglass balls on eBay US and I'm sure you have bought the first rate products the Shay Group produces, they don't offer this glass at present

Maybe try Pinball Rescue for the backglass?