The pinion shaft you have posted is aftermarket and has a slinger that looks to be a part of it, sometimes there removable. Because you stated that there were no shims with the manufacturer pinion, the slinger acts as a shim as well. Therefore you would need a slinger that is .009 thinner than what you have now.
You also asked if you could machine the slinger to make it fit, that's where the pinion shaft machining came in. We are just stating what you have said. We're hear to help, but telling people they do not know about gears and should not post is not going to get you anywhere, and it also makes you a hypocrite, because if you knew anything about gears, you would know that your slinger is too large, is acting as a shim, and needs to be replaced with a slinger that is .009 thinner than the current one.
Again, I'm not here to dog on you, just stating facts. We're more than happy to help. But appreciate the advice, if any when it's given.