Title seems a bit clickbaity but it's basically what happened. Last year two things happened to my collection, 1. I built a train out of Legos, and 2. I got a Railking Big Boy. Now I wanted to buy one of the Railking aux tenders to go with it but honestly those things are both too rare and too expensive, especially on that one auction site. My experience with the Lego train got me thinking though, and a few hours later I had the design worked out, not entirely accurate to the original but close enough:
I decided to check and see how much the bricks would cost, and the total would be around $30 give or take. I figured I could borrow some trucks from my Lego Liner until I got more suitable ones so I decided to go for it. Fast forward to today, and it's been built! While it's definitely not perfectly scaled (O gauge trains are around 7 studs wide, this car is 6) wide, it's close enough that it looks great in my opinion:
Any future upgrades for this will definitely be to get some 6 wheel trucks instead of 4 wheel ones, and to possibly redesign it to be a 7 stud wide car so it's more in scale with the engine and cars. For now, it will suffice