The difference is, not many volume O-scale model train producers left, AAMOF, just one! So, I don't know where you're going to buy when you desert Lionel.
OTOH, lots of other gun manufacturers, so there are plenty of choices.
Might be time to get 3rd Rail back into the freight market, but in plastic in lieu of brass.
OTOH, there can only be one. I am a diehard Walther owner in 5 calibers.
On a more serious note, I have found brass freight American Scale Models trucks in 2R on the bay at $40 a pair in many accurate styles have me replacing several trucks these days as they look so much better than anything cast. Biggest challenge is the bolster. I tried converting a pair of N5b trucks using the official L 2r conversion kit and the axles are too long for the frame spacing so they sit at a slight angle.