Bruce and Don
I really like my K-Line cars a lot. I never bought any engines because I was worried about spare parts. I only collect certain types of K-Line cars like only 21"ATSF passenger, NO COAL HOPPERS, most 4 bay grain hoppers, certain 2 bay grain hoppers, no box cars or refers, Certain Tank cars. So I do like the K-Line product but have tryrf to manage the collection a bit or I would need a warehouse for them 
