HO Mehano Jouef Locomotives

I have an HO scale Jouef Alstom PBA and PBKA locomotives, and I’m going to modify them. They look nice on the outside but are horrible on the inside. First of all they are too light that it’s a freaking joke! So I I’m gonna add lots and lots of weight to the whole train set. Bachmann produced its HO Spectrum Acela express. I believe the powered locomotive used to have a metal chassis on the inside. They don’t make the metal chassis anymore in the newer production models. I am looking for the manufacturer’s parts. Which vendor does produce a metal chassis that is either universal or that can fit into the Jouef Alstom PBA and PBKA locomotives. The dimensional coordinates should be very close to the models like the legnth and width of the metal chassis. I don’t care if the metal chassis is made for a specific brand like Athearn, Atlas, Walthers etc as long as it can fit inside the shell of the Jouef Alstom PBA and PBKA locomotives. I will glue the metal chassis to the base. I will purchase from their parts department. Any help appreciated. Thank You.

I would have thought you would be better off adding weight to the existing plastic chassis. My son has the Hornby Eurostart train set grade model and it also has a plastic chassis. We added some weight (wheel balancing weights), enough for better stability but not so much to over stress the motor. If your model is a recent Jouef, it is in all likelihood made in the same Chinese factory as the Eurostar as Jouef is part of Hornby. I am curious, does Jouef make the sets that are sold under the Mehano brand?