I forgot that you have Kleinow Boston in the 350/460 batch due to the Drum 350 find. That was throwing me for a loop in this.
In the simplest terms, I find it unlikely due to the lack of proof that any have been seen or graded. I know that sounds weak but that's the only true real evidence we can go with.
Do we have an idea of when the 460 print runs occurred or the order in which they occurred? If the EPDG print run was early, I could see a scenario where it's possible.....namely the intent to keep the Kleinow NY catching as part of the 460 and then switch over to Boston when the trade occurred, all while the EPDG were being printed for the 460's.