ge_rik
British narrow gauge (esp. Southwold and W&LLR)
If you only want basic functions (fwd, reverse, stop, start) and don't mind doing a bit of fettling, you could try using the guts from a cheap RC car such as this one
	
	
		
			
				
					
						
					
				
			
			
				
		
	
I've not tried it myself, but I know of others who have done so.
Rik
	
		
			
		
		
	
				
			
					
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			I've not tried it myself, but I know of others who have done so.
Rik