Tank car era question

[jwb]

Here is my Train Line Bakers Chocolate tank car:

   

There are a couple of things that need to be done to improve the car's reliability. One is to get rid of the little detent buttons or whatever you call them that hold the trucks on, fill in the bolster holes, and drill out for real screws. Here this is in progress on my BCOL diesel fuel car, which has had the bolster holes filled with plastic sprue from some kit:

   

Here is the result on my Bakers Chocolate car:

   

I also replaced the stock couplers with Kadee 158s and painted the trucks and wheels. The car is also too light, but I haven't been able to figure out how to open the body to add weight.