No! Weltz Amfleet was made by Elliot Weltz himself. There are too many distiguishing featchers between a Weltz Amfleet car and a Williams Amfleet car.
It is normal that some car ends are slightly warped and/or in your case could have been warped by the heat generated from the lighted interior. There are no known parts source other than to "Rob Peter to pay Paul" or find a junker and strip it of its usable parts. Its been like that since Elliot Weltz past away last Century.
Fwiw, you MIGHT be able to bash a Williams Amfleet end into the Weltz Amfleet end. I prrsonaly have NOT tried this.