On some of the steamers the tenders are the power plants, but the tender wheels no longer grip and make noise are the just to be replaced with kits of somekind or new wheels?

where are the model numbers put ?

I have 2 locomotives I need help with? 1st, prairie 2-6-2 & tender what holds the drivers to the wheels, (one sides off came that way)  2nd santa fe usra 0-6-0 switcher & tender, works a little bit but I think my issue is the power to the engine and or tender through the bus bar, ( doesent look to be a good connection,) (came that way) I saw drawing but need advice, Thx.