Ok I will correct you. Vekoma made one of these as recently as 2018, and they still offer them on their web site. The Mine Train is actually one of Vekoma's most popular models, and they clearly copied/took inspiration from the old Arrow Mine Trains of the past. (Granted the newest Mine Trains from Vekoma are computer designed and such, and thus are probably way smoother than the older Arrow models)
https://www.vekoma.com/mine-train-coasters
PS- Adventure Express IMO serves a spot in KI's lineup. It is a fairly popular ride with good reliability and great capacity and also a cult following, and while 30 years is old age for most steel coasters, Mine Trains can go 50+ so AE is actually only middle aged.